ABC problem: Difference between revisions

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(→‎{{header|JavaScript}}: ES6 by functional composition (Trans Haskell))
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=={{header|JavaScript}}==
=={{header|JavaScript}}==
===Regex===
===ES5===
====Imperative====
The following method uses regular expressions and the string replace function to allow more support for older browsers.
The following method uses regular expressions and the string replace function to allow more support for older browsers.
<lang javascript>var blocks = "BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM";
<lang javascript>var blocks = "BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM";
Line 2,830: Line 2,831:
</pre>
</pre>


===Functional (ES 5)===
====Functional====

<lang JavaScript>(function (strWords) {
<lang JavaScript>(function (strWords) {


Line 2,880: Line 2,880:


})('A bark BooK TReAT COMMON squAD conFUSE');</lang>
})('A bark BooK TReAT COMMON squAD conFUSE');</lang>

{{Out}}
{{Out}}

<lang JavaScript>A -> NA
<lang JavaScript>A -> NA
bark -> BO NA RE XK
bark -> BO NA RE XK
Line 2,892: Line 2,890:


===ES6===
===ES6===
====Imperative====
<lang javascript>let characters = "BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM";
<lang javascript>let characters = "BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM";
let blocks = characters.split(" ").map(pair => pair.split(""));
let blocks = characters.split(" ").map(pair => pair.split(""));
Line 2,934: Line 2,933:
SQUAD: true
SQUAD: true
CONFUSE: true</pre>
CONFUSE: true</pre>


====Functional====
{{Trans|Haskell}}
<lang JavaScript>(() => {
'use strict';

// ABC BLOCKS -------------------------------------------------------------

// spellWith :: [(Char, Char)] -> [Char] -> [[(Char, Char)]]
const spellWith = (blocks, wordChars) => {
if (isNull(wordChars)) {
return [
[]
];
} else {
const [x, xs] = uncons(wordChars);
return concatMap(
b => elem(x, b) ? concatMap(
bs => [cons(b, bs)],
spellWith(
deleteBy(
(p, q) => (p[0] === q[0]) && (p[1] === q[1]),
b, blocks
),
xs
)
) : [],
blocks
);
}
};

// GENERIC FUNCTIONS ------------------------------------------------------

// compose :: [(a -> a)] -> (a -> a)
const compose = fs => x => fs.reduceRight((a, f) => f(a), x);

// concatMap :: (a -> [b]) -> [a] -> [b]
const concatMap = (f, xs) => [].concat.apply([], xs.map(f));

// cons :: a -> [a] -> [a]
const cons = (x, xs) => [x].concat(xs);

// curry :: Function -> Function
const curry = (f, ...args) => {
const go = xs => xs.length >= f.length ? (f.apply(null, xs)) :
function () {
return go(xs.concat([].slice.apply(arguments)));
};
return go([].slice.call(args, 1));
};

// deleteBy :: (a -> a -> Bool) -> a -> [a] -> [a]
const deleteBy = (f, x, xs) =>
xs.length > 0 ? (
f(x, xs[0]) ? (
xs.slice(1)
) : [xs[0]].concat(deleteBy(f, x, xs.slice(1)))
) : [];

// elem :: Eq a => a -> [a] -> Bool
const elem = (x, xs) => xs.indexOf(x) !== -1;

// isNull :: [a] -> Bool
const isNull = xs => (xs instanceof Array) ? xs.length < 1 : undefined;

// map :: (a -> b) -> [a] -> [b]
const map = (f, xs) => xs.map(f);

// not :: Bool -> Bool
const not = b => !b;

// show :: a -> String
const show = x => JSON.stringify(x); //, null, 2);

// stringChars :: String -> [Char]
const stringChars = s => s.split('');

// toUpper :: Text -> Text
const toUpper = s => s.toUpperCase();

// uncons :: [a] -> Maybe (a, [a])
const uncons = xs => xs.length ? [xs[0], xs.slice(1)] : undefined;

// unlines :: [String] -> String
const unlines = xs => xs.join('\n');

// words :: String -> [String]
const words = s => s.split(/\s+/);

// TEST -------------------------------------------------------------------
// blocks :: [(Char, Char)]
const blocks = words(
"BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM"
);

return unlines(map(
x => show([x, compose(
[not, isNull, curry(spellWith)(blocks), stringChars, toUpper]
)(x)]), ["", "A", "BARK", "BoOK", "TrEAT", "COmMoN", "SQUAD", "conFUsE"]
));
})();
</lang>
{{Out}}
<pre>["",true]
["A",true]
["BARK",true]
["BoOK",false]
["TrEAT",true]
["COmMoN",false]
["SQUAD",true]
["conFUsE",true]</pre>


=={{header|jq}}==
=={{header|jq}}==

Revision as of 01:45, 24 March 2017

Task
ABC problem
You are encouraged to solve this task according to the task description, using any language you may know.

You are given a collection of ABC blocks   (maybe like the ones you had when you were a kid).

There are twenty blocks with two letters on each block.

A complete alphabet is guaranteed amongst all sides of the blocks.

The sample collection of blocks:

 (B O)
 (X K)
 (D Q)
 (C P)
 (N A)
 (G T)
 (R E)
 (T G)
 (Q D)
 (F S)
 (J W)
 (H U)
 (V I)
 (A N)
 (O B)
 (E R)
 (F S)
 (L Y)
 (P C)
 (Z M)


Task

Write a function that takes a string (word) and determines whether the word can be spelled with the given collection of blocks.


The rules are simple:

  1.   Once a letter on a block is used that block cannot be used again
  2.   The function should be case-insensitive
  3.   Show the output on this page for the following 7 words in the following example


Example

<lang python> >>> can_make_word("A")

   True
   >>> can_make_word("BARK")
   True
   >>> can_make_word("BOOK")
   False
   >>> can_make_word("TREAT")
   True
   >>> can_make_word("COMMON")
   False
   >>> can_make_word("SQUAD")
   True
   >>> can_make_word("CONFUSE")
   True</lang>



360 Assembly

The program uses one ASSIST macro (XPRNT) to keep the code as short as possible. <lang 360asm>* ABC Problem 21/07/2016 ABC CSECT

        USING  ABC,R13            base register
        B      72(R15)            skip savearea
        DC     17F'0'             savearea
        STM    R14,R12,12(R13)    prolog
        ST     R13,4(R15)         " <-
        ST     R15,8(R13)         " ->
        LR     R13,R15            " addressability
        LA     R8,1               l=1

LOOPL C R8,=A(NN) do l=1 to hbound(words)

        BH     ELOOPL
        LR     R1,R8              l
        MH     R1,=H'20'          *20
        LA     R10,WORDS-20(R1)   @words(l)
        MVC    STATUS,=CL5'true'  cflag='true'
        MVC    TBLOCKS,BLOCKS     tblocks=blocks
        MVC    CC(1),0(R10)       cc=substr(words(l),1,1)
        LA     R6,1               i=1

LOOPI CLI CC,C' ' do while cc<>' '

        BE     ELOOPI
        SR     R7,R7              k=0
        LH     R0,=H'1'           m=1

LOOPM CH R0,=AL2(L'TBLOCKS) do m=1 to length(tblocks)

        BH     ELOOPM
        LA     R5,TBLOCKS-1       @tblocks[0]
        AR     R5,R0              @tblocks[m]
        CLC    0(1,R5),CC         if substr(tblocks,m,1)=cc
        BNE    INDEXM
        LR     R7,R0              k=m=index(tblocks,cc)
        B      ELOOPM

INDEXM AH R0,=H'1' m=m+1

        B      LOOPM

ELOOPM LTR R7,R7 if k=0

        BNZ    OKK
        MVC    STATUS,=CL5'false' cflag='false'
        B      EIFK0

OKK LA R4,TBLOCKS-2 @tblocks[-1]

        AR     R4,R7              +k
        CLI    0(R4),C'('         if substr(tblocks,k-1,1)='('
        BNE    SECOND
        LA     R0,1               j=1
        B      EIFBLOCK

SECOND LA R0,3 j=3 EIFBLOCK LR R2,R7 k

        SR     R2,R0              k-j
        LA     R4,TBLOCKS-1       @tblocks[0]
        AR     R4,R2              @tblocks[k-j]
        MVC    0(5,R4),=CL5' '    substr(tblocks,k-j,5)='     '

EIFK0 LA R6,1(R6) i=i+1

        LR     R4,R10             @words
        AR     R4,R6              +i
        BCTR   R4,0               -1
        MVC    CC,0(R4)           cc=substr(words,i,1)
        B      LOOPI

ELOOPI MVC PG(20),0(R10) tabword(l)

        MVC    PG+20(5),STATUS    status
        XPRNT  PG,80              print buffer
        LA     R8,1(R8)           l=l+1
        B      LOOPL

ELOOPL L R13,4(0,R13) epilog

        LM     R14,R12,12(R13)    " restore
        XR     R15,R15            " rc=0
        BR     R14                exit

WORDS DC CL20'A',CL20'BARK',CL20'BOOK',CL20'TREAT',CL20'COMMON'

        DC     CL20'SQUAD',CL20'CONFUSE'

BLOCKS DS 0CL122

DC CL61'((B O) (X K) (D Q) (C P) (N A) (G T) (R E) (T G) (Q D) (F S) '
DC CL61'(J W) (H U) (V I) (A N) (O B) (E R) (F S) (L Y) (P C) (Z M)) '

TBLOCKS DS CL(L'BLOCKS) work blocks CC DS CL1 letter to find STATUS DS CL5 true/false PG DC CL80' ' buffer

        YREGS

NN EQU (BLOCKS-WORDS)/L'WORDS number of words

        END    ABC</lang>
Output:
A                   true
BARK                true
BOOK                false
TREAT               true
COMMON              false
SQUAD               true
CONFUSE             true

Acurity Architect

Using #HASH-OFF

<lang acurity architect> FUNCTION bCAN_MAKE_WORD(zWord: STRING): BOOLEAN

 VAR sBlockCount: SHORT
 VAR sWordCount: SHORT
 VAR sWordLength: SHORT
 VAR zLetter: STRING
 VAR zBlock: STRING
 VAR zBlockList: STRING
 VAR zUsedBlocks: STRING
 VAR zWord: STRING
 //
 SET zWord = UPPER(zWord)
 SET zBlockList = "BO,XK,DQ,CP,NA,GT,RE,TG,QD,FS,JW,HU,VI,AN,OB,ER,FS,LY,PC,ZM"
 SET sWordLength = LENGTH(zWord)
 //
 DO sWordCount = 1 TO sWordLength
   DO sBlockCount = 1 TO OCCURS(zBlockList, ",")
     SET zLetter = SUBSTR(zWord, sWordCount, 1)
     SET zBlock = GET_TOKEN(zBlockList, ",", sBlockCount)
     IF INDEX(zBlock, zLetter, 1) > 0 AND INDEX(zUsedBlocks, zBlock + STR(sBlockCount), 1) = 0
       SET zUsedBlocks = zUsedBlocks + zBlock + STR(sBlockCount) + ","
       BREAK
     ENDIF
   ENDDO
 ENDDO
 RETURN OCCURS(zUsedBlocks, ",") = sWordLength 

ENDFUNCTION </lang>

Output:
bCAN_MAKE_WORD("A") returns TRUE
bCAN_MAKE_WORD("BARK") returns TRUE
bCAN_MAKE_WORD("BOOK") returns FALSE
bCAN_MAKE_WORD("TREAT") returns TRUE
bCAN_MAKE_WORD("COMMON") returns FALSE
bCAN_MAKE_WORD("SQUAD") returns TRUE
bCAN_MAKE_WORD("CONFUSE") returns TRUE

Ada

Build with gnatchop abc.ada; gnatmake abc_problem

<lang ada>with Ada.Characters.Handling; use Ada.Characters.Handling;


package Abc is

   type Block_Faces is array(1..2) of Character;
   type Block_List is array(positive range <>) of Block_Faces;
   function Can_Make_Word(W: String; Blocks: Block_List) return Boolean;

end Abc;


package body Abc is

function Can_Make_Word(W: String; Blocks: Block_List) return Boolean is

   Used : array(Blocks'Range) of Boolean := (Others => False);
   subtype wIndex is Integer range W'First..W'Last;
   wPos : wIndex;

begin

   if W'Length = 0 then
       return True;
   end if;
   wPos := W'First;
   while True loop
       declare
           C : Character := To_Upper(W(wPos));
           X : constant wIndex := wPos;
       begin
           for I in Blocks'Range loop
               if (not Used(I)) then
                   if C = To_Upper(Blocks(I)(1)) or C = To_Upper(Blocks(I)(2)) then
                       Used(I) := True;
                       if wPos = W'Last then
                           return True;
                       end if;
                       wPos := wIndex'Succ(wPos);
                       exit;
                   end if;
               end if;
           end loop;
           if X = wPos then
               return False;
           end if;
       end;
   end loop;
   return False;

end Can_Make_Word;

end Abc;

with Ada.Text_IO, Ada.Strings.Unbounded, Abc; use Ada.Text_IO, Ada.Strings.Unbounded, Abc;

procedure Abc_Problem is

   Blocks : Block_List := (
         ('B','O'), ('X','K'), ('D','Q'), ('C','P')
       , ('N','A'), ('G','T'), ('R','E'), ('T','G')
       , ('Q','D'), ('F','S'), ('J','W'), ('H','U')
       , ('V','I'), ('A','N'), ('O','B'), ('E','R')
       , ('F','S'), ('L','Y'), ('P','C'), ('Z','M')
   );
   function "+" (S : String) return Unbounded_String renames To_Unbounded_String;
   words : array(positive range <>) of Unbounded_String := (
         +"A"
       , +"BARK"
       , +"BOOK"
       , +"TREAT"
       , +"COMMON"
       , +"SQUAD"
       , +"CONFUSE"
       -- Border cases:
       -- , +"CONFUSE2"
       -- , +""
   );

begin

   for I in words'Range loop
       Put_Line ( To_String(words(I)) & ": " & Boolean'Image(Can_Make_Word(To_String(words(I)),Blocks)) );
   end loop;

end Abc_Problem; </lang>

Output:
A: TRUE
BARK: TRUE
BOOK: FALSE
TREAT: TRUE
COMMON: FALSE
SQUAD: TRUE
CONFUSE: TRUE

ALGOL 68

Works with: ALGOL 68G version Any - tested with release 2.8.win32

<lang algol68># determine whether we can spell words with a set of blocks #

  1. construct the list of blocks #

[][]STRING blocks = ( ( "B", "O" ), ( "X", "K" ), ( "D", "Q" ), ( "C", "P" )

                   , ( "N", "A" ), ( "G", "T" ), ( "R", "E" ), ( "T", "G" )
                   , ( "Q", "D" ), ( "F", "S" ), ( "J", "W" ), ( "H", "U" )
                   , ( "V", "I" ), ( "A", "N" ), ( "O", "B" ), ( "E", "R" )
                   , ( "F", "S" ), ( "L", "Y" ), ( "P", "C" ), ( "Z", "M" )
                   );
  1. Returns TRUE if we can spell the word using the blocks, FALSE otherwise #
  2. Returns TRUE for an empty string #

PROC can spell = ( STRING word, [][]STRING blocks )BOOL:

   BEGIN
       # construct a set of flags to indicate whether the blocks are used   #
       # or not                                                             #
       [ 1 LWB blocks : 1 UPB blocks ]BOOL used;
       FOR block pos FROM LWB used TO UPB used
       DO
           used[ block pos ] := FALSE
       OD;
       # initialliy assume we can spell the word                            #
       BOOL result := TRUE;
       # check we can spell the word with the set of blocks                 #
       FOR word pos FROM LWB word TO UPB word WHILE result
       DO
           CHAR c = IF   is lower( word[ word pos ] )
                    THEN to upper( word[ word pos ] )
                    ELSE           word[ word pos ]
                    FI;
           # look through the unused blocks for the current letter          #
           BOOL found := FALSE;
           FOR block pos FROM 1 LWB blocks TO 1 UPB blocks
           WHILE NOT found
           DO
               IF  (  c = blocks[ block pos ][ 1 ][ 1 ]
                   OR c = blocks[ block pos ][ 2 ][ 1 ]
                   )
               AND NOT used[ block pos ]
               THEN
                   # found an unused block with the required letter         #
                   found             := TRUE;
                   used[ block pos ] := TRUE
               FI
           OD;
           result := found
       OD;
       result
   END; # can spell #


main: (

   # test the can spell procedure                                           #
   PROC test can spell = ( STRING word, [][]STRING blocks )VOID:
       write( ( ( "can spell: """
                + word
                + """ -> "
                + IF can spell( word, blocks ) THEN "yes" ELSE "no" FI
                )
              , newline
              )
            );
   test can spell( "A",       blocks );
   test can spell( "BaRK",    blocks );
   test can spell( "BOOK",    blocks );
   test can spell( "TREAT",   blocks );
   test can spell( "COMMON",  blocks );
   test can spell( "SQUAD",   blocks );
   test can spell( "CONFUSE", blocks )

) </lang> Output:

can spell: "A" -> yes
can spell: "BaRK" -> yes
can spell: "BOOK" -> no
can spell: "TREAT" -> yes
can spell: "COMMON" -> no
can spell: "SQUAD" -> yes
can spell: "CONFUSE" -> yes

ALGOL W

<lang algolw>% determine whether we can spell words with a set of blocks  % begin

   % Returns true  if we can spell the word using the blocks,               %
   %         false otherwise                                                %
   % As strings are fixed length in Algol W, the length of the string is    %
   % passed as a separate parameter                                         %
   logical procedure canSpell ( string(20) value word
                              ; integer    value wordLength
                              ) ;
   begin
       % convert a character to upper-case                                  %
       % assumes the letters are contiguous in the character set            %
       % as in ASCII and Unicode - not correct for EBCDIC                   %
       string(1) procedure toUpper( string(1) value c ) ;
           if c < "a" or c > "z" then c
                                 else code( ( decode( c ) - decode( "a" ) )
                                          + decode( "A" )
                                          ) ;
       logical       spellable;
       integer       wordPos,  blockPos;
       string(20)    letters1, letters2;
       % make local copies the faces so we can remove the used blocks       %
       letters1 := face1;
       letters2 := face2;
       % check we can spell the word with the set of blocks                 %
       spellable := true;
       wordPos   := 0;
       while wordPos < wordLength and spellable do begin
           string(1) letter;
           letter    := toUpper( word( wordPos // 1 ) );
           if letter not = " " then begin
               spellable := false;
               blockPos  := 0;
               while blockPos < 20 and not spellable do begin
                   if letter = letters1( blockPos // 1 )
                   or letter = letters2( blockPos // 1 )
                   then begin
                       % found the letter - remove the used block from the  %
                       % remaining blocks                                   %
                       letters1( blockPos // 1 ) := " ";
                       letters2( blockPos // 1 ) := " ";
                       spellable := true
                   end;
                   blockPos := blockPos + 1
               end
           end;
           wordPos := wordPos + 1;
       end;
       spellable
   end canSpell ;
   % the letters available on the faces of the blocks                       %
   string(20) face1, face2;
   face1 := "BXDCNGRTQFJHVAOEFLPZ";
   face2 := "OKQPATEGDSWUINBRSYCM";
   begin
       % test the can spell procedure                                       %
       procedure testCanSpell ( string(20) value word
                              ; integer    value wordLength
                              ) ;
           write( if canSpell( word, wordLength ) then "can   " else "cannot"
                , " spell """
                , word
                , """"
                );
       testCanSpell( "a",       1 );
       testCanSpell( "bark",    4 );
       testCanSpell( "BOOK",    4 );
       testCanSpell( "treat",   5 );
       testCanSpell( "commoN",  6 );
       testCanSpell( "Squad",   5 );
       testCanSpell( "confuse", 7 )
   end

end.</lang>

Output:
can    spell "a                   "
can    spell "bark                "
cannot spell "BOOK                "
can    spell "treat               "
cannot spell "commoN              "
can    spell "Squad               "
can    spell "confuse             "

Apex

<lang Java>static Boolean canMakeWord(List<String> src_blocks, String word) {

   if (String.isEmpty(word)) {
       return true;
   }
   List<String> blocks = new List<String>();
   for (String block : src_blocks) {
       blocks.add(block.toUpperCase());
   }
   
   for (Integer i = 0; i < word.length(); i++) {
       Integer blockIndex = -1;
       String c = word.mid(i, 1).toUpperCase();
       
       for (Integer j = 0; j < blocks.size(); j++) {
           if (blocks.get(j).contains(c)) {
               blockIndex = j;
               break;
           }
       }
       
       if (blockIndex == -1) {
           return false;
       } else {
           blocks.remove(blockIndex);
       }
   }
       
   return true;

}

List<String> blocks = new List<String>{

   'BO', 'XK', 'DQ', 'CP', 'NA',
   'GT', 'RE', 'TG', 'QD', 'FS', 
   'JW', 'HU', 'VI', 'AN', 'OB', 
   'ER', 'FS', 'LY', 'PC', 'ZM'

}; System.debug('"": ' + canMakeWord(blocks, )); System.debug('"A": ' + canMakeWord(blocks, 'A')); System.debug('"BARK": ' + canMakeWord(blocks, 'BARK')); System.debug('"book": ' + canMakeWord(blocks, 'book')); System.debug('"treat": ' + canMakeWord(blocks, 'treat')); System.debug('"COMMON": ' + canMakeWord(blocks, 'COMMON')); System.debug('"SQuAd": ' + canMakeWord(blocks, 'SQuAd')); System.debug('"CONFUSE": ' + canMakeWord(blocks, 'CONFUSE'));</lang>

Output:
"": true
"A": true
"BARK": true
"book": false
"treat": true
"COMMON": false
"SQuAd": true
"CONFUSE": true

AppleScript

<lang AppleScript>set blocks to {"bo", "xk", "dq", "cp", "na", "gt", "re", "tg", "qd", "fs", "jw", "hu", "vi", "an", "ob", "er", "fs", "ly", "pc", "zm"}

canMakeWordWithBlocks("a", blocks) canMakeWordWithBlocks("bark", blocks) canMakeWordWithBlocks("book", blocks) canMakeWordWithBlocks("treat", blocks) canMakeWordWithBlocks("common", blocks) canMakeWordWithBlocks("squad", blocks) canMakeWordWithBlocks("confuse", blocks)

on canMakeWordWithBlocks(theString, constBlocks) copy constBlocks to theBlocks if theString = "" then return true set i to 1 repeat if i > (count theBlocks) then exit repeat if character 1 of theString is in item i of theBlocks then set item i of theBlocks to missing value set theBlocks to strings of theBlocks if canMakeWordWithBlocks(rest of characters of theString as string, theBlocks) then return true end if end if set i to i + 1 end repeat return false end canMakeWordWithBlocks </lang>

AutoHotkey

Function <lang autohotkey>isWordPossible(blocks, word){ o := {} loop, parse, blocks, `n, `r o.Insert(A_LoopField) loop, parse, word if !(r := isWordPossible_contains(o, A_LoopField, word)) return 0 return 1 } isWordPossible_contains(byref o, letter, word){ loop 2 { for k,v in o if Instr(v,letter) { StringReplace, op, v,% letter if RegExMatch(op, "[" word "]") sap := k else added := 1 , sap := k if added return "1" o.remove(sap) } added := 1 } }</lang>

Test Input (as per question) <lang autohotkey>blocks := " ( BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM )"

wordlist := " ( A BARK BOOK TREAT COMMON SQUAD CONFUSE )"

loop, parse, wordlist, `n out .= A_LoopField " - " isWordPossible(blocks, A_LoopField) "`n" msgbox % out</lang>

Output:
A - 1
BARK - 1
BOOK - 0
TREAT - 1
COMMON - 0
SQUAD - 1
CONFUSE - 1

Batch File

<lang dos> @echo off

abc.bat
Batch file to evaluate if a given string can be represented with a set of
20 2-faced blocks.
Check if a string was provided

if "%1"=="" goto ERROR

Define blocks. Separate blocks by ':', and terminat with '::'

set "FACES=BO:XK:DQ:CP:NA:GT:RE:TG:QD:FS:JW:HU:VI:AN:OB:ER:FS:LY:PC:ZM::" set INPUT=%1 set "COUNTER=0"

The main loop steps through the input string, checking if an available
block exists for each character
LOOP_MAIN
 ::Get character, increase counter, and test if there are still characters
 call set "char=%%INPUT:~%COUNTER%,1%%"
 set /a "COUNTER+=1"
 if "%CHAR%"=="" goto LOOP_MAIN_END
 set "OFFSET=0"
 :LOOP_2
   ::Read in two characters (one block)
   call set "BLOCK=%%FACES%:~%OFFSET%,2%%"
   ::Test if the all blocks were checked. If so, no match was found
   if "%BLOCK%"==":" goto FAIL
   ::Test if current input string character is in the current block
   if /i "%BLOCK:~0,1%"=="%CHAR%" goto FOUND
   if /i "%BLOCK:~1,1%"=="%CHAR%" goto FOUND
   ::Increase offset to point to the next block
   set /a "OFFSET+=3"
 goto LOOP_2
 :LOOP_2_END
 ::If found, blank out the block used
 :FOUND
 call set "FACES=%%FACES:%BLOCK%:=  :%%"

goto LOOP_MAIN

LOOP_MAIN_END

echo %0: It is possible to write the '%INPUT%' with my blocks. goto END

FAIL

echo %0: It is NOT possible to write the '%INPUT%' with my blocks. goto END

ERROR

echo %0: Please enter a string to evaluate echo.

END

</lang>

BASIC

Works with:VB-DOS, QB64, QBasic, QuickBASIC <lang qbasic> ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ABC_Problem ' ' ' ' Developed by A. David Garza Marín in VB-DOS for ' ' RosettaCode. November 29, 2016. ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' '

' Comment the following line to run it in QB or QBasic OPTION EXPLICIT ' Modify to OPTION _EXPLICIT for QB64

' SUBs and FUNCTIONs DECLARE SUB doCleanBlocks () DECLARE FUNCTION ICanMakeTheWord (WhichWord AS STRING) AS INTEGER DECLARE SUB doReadBlocks ()

' rBlock Data Type TYPE regBlock

 Block AS STRING * 2
 Used AS INTEGER

END TYPE

' Initialize CONST False = 0, True = NOT False, HMBlocks = 20 DATA "BO", "XK", "DQ", "CP", "NA", "GT","RE", "TG" DATA "QD", "FS", "JW", "HU", "VI", "AN", "OB", "ER" DATA "FS", "LY", "PC","ZM"

DIM rBlock(1 TO HMBlocks) AS regBlock DIM i AS INTEGER, aWord AS STRING, YorN AS STRING

doReadBlocks ' Read the data in the blocks

'-------------- Main program cycle ------------------ CLS PRINT "This program has the following blocks: "; FOR i = 1 TO HMBlocks

 PRINT rBlock(i).Block; "|";

NEXT i PRINT : PRINT PRINT "Please, write a word or a short sentence to see if the available" PRINT "blocks can make it. If so, I will tell you." DO

 doCleanBlocks ' Clean all blocks
 PRINT
 INPUT "Which is the word"; aWord
 aWord = LTRIM$(RTRIM$(aWord))
 IF aWord <> "" THEN
   IF ICanMakeTheWord(aWord) THEN
     PRINT "Yes, i can make it."
   ELSE
     PRINT "No, I can't make it."
   END IF
 ELSE
   PRINT "At least, you need to type a letter."
 END IF
 PRINT
 PRINT "Do you want to try again (Y/N) ";
 DO
   YorN = INPUT$(1)
   YorN = UCASE$(YorN)
 LOOP UNTIL YorN = "Y" OR YorN = "N"
 PRINT YorN

LOOP UNTIL YorN = "N" ' -------------- End of Main program ---------------- END

SUB doCleanBlocks ()

 ' Var
 SHARED rBlock() AS regBlock
 DIM i AS INTEGER
 ' Will clean the Used status of all blocks
 FOR i = 1 TO HMBlocks
   rBlock(i).Used = False
 NEXT i

END SUB

SUB doReadBlocks ()

 ' Var
 SHARED rBlock() AS regBlock
 DIM i AS INTEGER
 ' Will read the block values from DATA
 FOR i = 1 TO HMBlocks
   READ rBlock(i).Block
 NEXT i

END SUB

FUNCTION ICanMakeTheWord (WhichWord AS STRING) AS INTEGER ' Comment AS INTEGER to run in QBasic, QB64 and QuickBASIC

 ' Var
 SHARED rBlock() AS regBlock
 DIM i AS INTEGER, l AS INTEGER, j AS INTEGER, iYesICan AS INTEGER
 DIM c AS STRING, sUWord AS STRING
 ' Will evaluate if can make the word
 sUWord = UCASE$(WhichWord)
 l = LEN(sUWord)
 i = 0
 DO
   i = i + 1
   iYesICan = False
   c = MID$(sUWord, i, 1)
   j = 0
   DO
     j = j + 1
     IF NOT rBlock(j).Used THEN
       iYesICan = (INSTR(rBlock(j).Block, c) > 0)
       rBlock(j).Used = iYesICan
     END IF
   LOOP UNTIL j >= HMBlocks OR iYesICan
 LOOP UNTIL i >= l OR NOT iYesICan
 ' The result will depend on the last value of
 '  iYesICan variable. If the last value is True
 '  is because the function found even the last
 '  letter analyzed.
 ICanMakeTheWord = iYesICan

END FUNCTION </lang>

BBC BASIC

<lang bbcbasic> BLOCKS$="BOXKDQCPNAGTRETGQDFSJWHUVIANOBERFSLYPCZM"

     PROCcan_make_word("A")
     PROCcan_make_word("BARK")
     PROCcan_make_word("BOOK")
     PROCcan_make_word("TREAT")
     PROCcan_make_word("COMMON")
     PROCcan_make_word("SQUAD")
     PROCcan_make_word("Confuse")
     END
     DEF PROCcan_make_word(word$)
     LOCAL b$,p%
     b$=BLOCKS$
     PRINT word$ " -> ";
     p%=INSTR(b$,CHR$(ASCword$ AND &DF))
     WHILE p%>0 AND word$>""
       MID$(b$,p%-1+(p% MOD 2),2)=".."
       word$=MID$(word$,2)
       p%=INSTR(b$,CHR$(ASCword$ AND &DF))
     ENDWHILE
     IF word$>"" PRINT "False" ELSE PRINT "True"
     ENDPROC</lang>
Output:
A -> True
BARK -> True
BOOK -> False
TREAT -> True
COMMON -> False
SQUAD -> True
Confuse -> True

Bracmat

<lang bracmat>(

 ( can-make-word
 =   ABC blocks
   .       (B O)
         + (X K)
         + (D Q)
         + (C P)
         + (N A)
         + (G T)
         + (R E)
         + (T G)
         + (Q D)
         + (F S)
         + (J W)
         + (H U)
         + (V I)
         + (A N)
         + (O B)
         + (E R)
         + (F S)
         + (L Y)
         + (P C)
         + (Z M)
       : ?blocks
     & ( ABC
       =   letter blocks A Z
         .   !arg:(.?)
           |   !arg:(@(?:%?letter ?arg).?blocks)
             &   !blocks
               :   ?
                 + ?*(? !letter ?:?block)
                 + (?&ABC$(!arg.!blocks+-1*!block))
       )
     &   out
       $ ( !arg
           ( ABC$(upp$!arg.!blocks)&yes
           | no
           )
         )
 )

& can-make-word'A & can-make-word'BARK & can-make-word'BOOK & can-make-word'TREAT & can-make-word'COMMON & can-make-word'SQUAD & can-make-word'CONFUSE );</lang>

Output:
A yes
BARK yes
BOOK no
TREAT yes
COMMON no
SQUAD yes
CONFUSE yes

C

Recursive solution. Empty string returns true. <lang c>#include <stdio.h>

  1. include <ctype.h>

int can_make_words(char **b, char *word) { int i, ret = 0, c = toupper(*word);

  1. define SWAP(a, b) if (a != b) { char * tmp = a; a = b; b = tmp; }

if (!c) return 1; if (!b[0]) return 0;

for (i = 0; b[i] && !ret; i++) { if (b[i][0] != c && b[i][1] != c) continue; SWAP(b[i], b[0]); ret = can_make_words(b + 1, word + 1); SWAP(b[i], b[0]); }

return ret; }

int main(void) { char* blocks[] = { "BO", "XK", "DQ", "CP", "NA", "GT", "RE", "TG", "QD", "FS", "JW", "HU", "VI", "AN", "OB", "ER", "FS", "LY", "PC", "ZM", 0 };

char *words[] = { "", "A", "BARK", "BOOK", "TREAT", "COMMON", "SQUAD", "Confuse", 0 };

char **w; for (w = words; *w; w++) printf("%s\t%d\n", *w, can_make_words(blocks, *w));

return 0; }</lang>

Output:
        1
A       1
BARK    1
BOOK    0
TREAT   1
COMMON  0
SQUAD   1
Confuse 1


C++

Uses C++11. Build with g++-4.7 -Wall -std=c++0x abc.cpp <lang cpp>#include <iostream>

  1. include <vector>
  2. include <string>
  3. include <set>
  4. include <cctype>


typedef std::pair<char,char> item_t; typedef std::vector<item_t> list_t;

bool can_make_word(const std::string& w, const list_t& vals) {

   std::set<uint32_t> used;
   while (used.size() < w.size()) {
       const char c = toupper(w[used.size()]);
       uint32_t x = used.size();
       for (uint32_t i = 0, ii = vals.size(); i < ii; ++i) {
           if (used.find(i) == used.end()) {
               if (toupper(vals[i].first) == c || toupper(vals[i].second) == c) {
                   used.insert(i);
                   break;
               }
           }
       }
       if (x == used.size()) break;
   }
   return used.size() == w.size();

}


int main() {

   list_t vals{ {'B','O'}, {'X','K'}, {'D','Q'}, {'C','P'}, {'N','A'}, {'G','T'}, {'R','E'}, {'T','G'}, {'Q','D'}, {'F','S'}, {'J','W'}, {'H','U'}, {'V','I'}, {'A','N'}, {'O','B'}, {'E','R'}, {'F','S'}, {'L','Y'}, {'P','C'}, {'Z','M'} };
   std::vector<std::string> words{"A","BARK","BOOK","TREAT","COMMON","SQUAD","CONFUSE"};
   for (const std::string& w : words) {
       std::cout << w << ": " << std::boolalpha << can_make_word(w,vals) << ".\n";
   }

}</lang>

Output:
A: true.
BARK: true.
BOOK: false.
TREAT: true.
COMMON: false.
SQUAD: true.
CONFUSE: true.

C#

Regex

This Method uses regular expressions to do the checking. Given that n = length of blocks string and m = length of word string, then CheckWord's time complexity comes out to about m*(n - (m-1)/2). <lang csharp>using System; using System.IO; // Needed for the method. using System.Text.RegularExpressions; using System.Collections.Generic;

void Main() {

  string blocks = "BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM";
  List<string> words = new List<string>() {
     "A", "BARK", "BOOK", "TREAT", "COMMON", "SQUAD", "CONFUSE"
  };
  foreach(var word in words)
  {
     Console.WriteLine("{0}: {1}", word, CheckWord(blocks, word));
  }

}

bool CheckWord(string blocks, string word) {

  for(int i = 0; i < word.Length; ++i)
  {
     int length = blocks.Length;
     Regex rgx = new Regex("([a-z]"+word[i]+"|"+word[i]+"[a-z])", RegexOptions.IgnoreCase);
     blocks = rgx.Replace(blocks, "", 1);
     if(blocks.Length == length) return false;
  }
  return true;

} </lang>

Output:
A: True
BARK: True
BOOK: False
TREAT: True
COMMON: False
SQUAD: True
CONFUSE: True

Unoptimized <lang csharp>using System.Collections.Generic; using System.Linq;

void Main() { List<string> blocks = new List<string>() { "bo", "xk", "dq", "cp", "na", "gt", "re", "tg", "qd", "fs", "jw", "hu", "vi", "an", "ob", "er", "fs", "ly", "pc", "zm" }; List<string> words = new List<string>() { "A", "BARK", "BOOK", "TREAT", "COMMON", "SQUAD", "CONFUSE"};

var solver = new ABC(blocks);

foreach( var word in words) { Console.WriteLine("{0} :{1}", word, solver.CanMake(word)); } }

class ABC { readonly Dictionary<char, List<int>> _blockDict = new Dictionary<char, List<int>>(); bool[] _used; int _nextBlock;

readonly List<string> _blocks;

private void AddBlockChar(char c) { if (!_blockDict.ContainsKey(c)) { _blockDict[c] = new List<int>(); } _blockDict[c].Add(_nextBlock); }

private void AddBlock(string block) { AddBlockChar(block[0]); AddBlockChar(block[1]); _nextBlock++; }

public ABC(List<string> blocks) { _blocks = blocks; foreach (var block in blocks) { AddBlock(block); } }

public bool CanMake(string word) { word = word.ToLower(); if (word.Length > _blockDict.Count) { return false; } _used = new bool[_blocks.Count]; return TryMake(word); }

public bool TryMake(string word) { if (word == string.Empty) { return true; } var blocks = _blockDict[word[0]].Where(b => !_used[b]); foreach (var block in blocks) { _used[block] = true; if (TryMake(word.Substring(1))) { return true; } _used[block] = false; } return false; } } </lang>

Output:
A :True
BARK :True
BOOK :False
TREAT :True
COMMON :False
SQUAD :True
CONFUSE :True

Ceylon

Functional programming/recursive solution. No variable values.

module.ceylon

<lang ceylon> module rosetta.abc "1.0.0" {} </lang>

run.ceylon

<lang ceylon> shared void run() {

   printAndCanMakeWord("A", blocks);
   //True
   printAndCanMakeWord("BARK", blocks);
   //True
   printAndCanMakeWord("BOOK", blocks);
   //False
   printAndCanMakeWord("TREAT", blocks);
   //True
   printAndCanMakeWord("COMMON", blocks);
   //False
   printAndCanMakeWord("SQUAD", blocks);
   //True
   printAndCanMakeWord("CONFUSE", blocks);
   //True

}

Block[] blocks =

   [
       Block('B','O'),
       Block('X','K'),
       Block('D','Q'),
       Block('C','P'),
       Block('N','A'),
       Block('G','T'),
       Block('R','E'),
       Block('T','G'),
       Block('Q','D'),
       Block('F','S'),
       Block('J','W'),
       Block('H','U'),
       Block('V','I'),
       Block('A','N'),
       Block('O','B'),
       Block('E','R'),
       Block('F','S'),
       Block('L','Y'),
       Block('P','C'),
       Block('Z','M')
   ];

void printAndCanMakeWord(String word, Block[] blocks) {

   print("``word``:``canMakeWord(word, blocks)``");

}

class Block(Character firstLetter, Character secondLetter) {

   shared Character firstLetterUpper = firstLetter.uppercased;
   shared Character secondLetterUpper = secondLetter.uppercased;
   shared Boolean containsLetter(Character letter)
       => let (letterUpper = letter.uppercased)
           firstLetterUpper == letterUpper || secondLetterUpper == letterUpper;
   shared actual String string = "``firstLetterUpper``,``secondLetterUpper``";

}

Boolean canMakeWord(String word, Block[] blocks)

   => canMakeWordRecursive(word.uppercased.sequence(), 0, blocks, word.indexes());

Boolean canMakeWordRecursive(Character[] word,

                            Integer index,
                            Block[] remainingBlocks,
                            Integer[] remainingLetterIndexes)
   => if (exists wordFirst = word.first, // first is the Ceylon attribute for head
          exists remainingBlock = remainingBlocks.find((remainingBlock) => remainingBlock.containsLetter(wordFirst)))
       then
           let (myRemainingLetterIndexes = remainingLetterIndexes.filter((theIndex) => index != theIndex).sequence())
            if (myRemainingLetterIndexes.empty)
                then true
                else canMakeWordRecursive(word.rest,// rest is the Ceylon attribute for tail
                                          index+1, // move through the letter indexes
                                          remainingBlocks.filter((block) => remainingBlock != block).sequence(), // one less block
                                          myRemainingLetterIndexes)
       else false;

</lang>

Output:
A:true
BARK:true
BOOK:false
TREAT:true
COMMON:false
SQUAD:true
CONFUSE:true

Clojure

A translation of the Haskell solution. <lang clojure> (def blocks

 (-> "BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM" (.split " ") vec))

(defn omit

 "return bs with (one instance of) b omitted"
 [bs b] 
 (let [[before after] (split-with #(not= b %) bs)]
   (concat before (rest after))))

(defn abc

 "return lazy sequence of solutions (i.e. block lists)"
 [blocks [c & cs]]
 (if (some? c)
   (for [b blocks :when (some #(= c %) b)
         bs (abc (omit blocks b) cs)]
     (cons b bs))
   [[]]))
   
     

(doseq [word ["A" "BARK" "Book" "treat" "COMMON" "SQUAD" "CONFUSE"]]

 (->> word .toUpperCase (abc blocks) first (printf "%s: %b\n" word)))</lang>
Output:
A: true
BARK: true
Book: false
treat: true
COMMON: false
SQUAD: true
CONFUSE: true

CoffeeScript

<lang CoffeeScript>blockList = [ 'BO', 'XK', 'DQ', 'CP', 'NA', 'GT', 'RE', 'TG', 'QD', 'FS', 'JW', 'HU', 'VI', 'AN', 'OB', 'ER', 'FS', 'LY', 'PC', 'ZM' ]

canMakeWord = (word="") ->

   # Create a shallow clone of the master blockList
   blocks = blockList.slice 0
   # Check if blocks contains letter
   checkBlocks = (letter) ->
       # Loop through every remaining block
       for block, idx in blocks
           # If letter is in block, blocks.splice will return an array, which will evaluate as true
           return blocks.splice idx, 1 if letter.toUpperCase() in block
       false
   # Return true if there are no falsy values
   false not in (checkBlocks letter for letter in word)
  1. Expect true, true, false, true, false, true, true, true

for word in ["A", "BARK", "BOOK", "TREAT", "COMMON", "squad", "CONFUSE", "STORM"]

   console.log word + " -> " + canMakeWord(word)</lang>
Output:
A -> true
BARK -> true
BOOK -> false
TREAT -> true
COMMON -> false
squad -> true
CONFUSE -> true
STORM -> true

Common Lisp

<lang lisp> (defun word-possible-p (word blocks)

 (cond 
   ((= (length word) 0) t)
   ((null blocks) nil)
   (t (let* 
        ((c (aref word 0))
         (bs (remove-if-not #'(lambda (b) 
                                (find c b :test #'char-equal))
                            blocks)))
        (some #'identity 
              (loop for b in bs
                    collect (word-possible-p
                              (subseq word 1)
                              (remove b blocks))))))))</lang>
Output:
> (defparameter *blocks* 
    '("BO" "XK" "DQ" "CP" "NA" "GT" "RE" "TG" "QD" "FS" 
      "JW" "HU" "VI" "AN" "OB" "ER" "FS" "LY" "PC" "ZM"))
> (dolist (w '("" "A" "bArk" "BOOK" "trEAt" "CoMmoN" "squad" "conFUse"))
    (format t "~s is possible: ~a~%" w (word-possible-p w *blocks*)))
"" is possible: T
"A" is possible: T
"bArk" is possible: T
"BOOK" is possible: NIL
"trEAt" is possible: T
"CoMmoN" is possible: NIL
"squad" is possible: T
"conFUse" is possible: T
NIL
> (word-possible-p "abba" '("AB" "AB" "AC" "AC"))
T

D

Basic Version

Translation of: Python

A simple greedy algorithm is enough for the given sequence of blocks. canMakeWord is true on an empty word because you can compose it using zero blocks. <lang d>import std.stdio, std.algorithm, std.string;

bool canMakeWord(in string word, in string[] blocks) pure /*nothrow*/ @safe {

   auto bs = blocks.dup;
   outer: foreach (immutable ch; word.toUpper) {
       foreach (immutable block; bs)
           if (block.canFind(ch)) {
               bs = bs.remove(bs.countUntil(block));
               continue outer;
           }
       return false;
   }
   return true;

}

void main() @safe {

   immutable blocks = "BO XK DQ CP NA GT RE TG QD FS JW HU VI
                       AN OB ER FS LY PC ZM".split;
   foreach (word; "" ~ "A BARK BoOK TrEAT COmMoN SQUAD conFUsE".split)
       writefln(`"%s" %s`, word, canMakeWord(word, blocks));

}</lang>

Output:
"" true
"A" true
"BARK" true
"BoOK" false
"TrEAT" true
"COmMoN" false
"SQUAD" true
"conFUsE" true

@nogc Version

The same as the precedent version, but it avoids all heap allocations and it's lower-level and ASCII-only. <lang d>import std.ascii, core.stdc.stdlib;

bool canMakeWord(in string word, in string[] blocks) nothrow @nogc in {

   foreach (immutable char ch; word)
       assert(ch.isASCII);
   foreach (const block; blocks)
       assert(block.length == 2 && block[0].isASCII && block[1].isASCII);

} body {

   auto ptr = cast(string*)alloca(blocks.length * string.sizeof);
   if (ptr == null)
       exit(1);
   auto blocks2 = ptr[0 .. blocks.length];
   blocks2[] = blocks[];
   outer: foreach (immutable i; 0 .. word.length) {
       immutable ch = word[i].toUpper;
       foreach (immutable j; 0 .. blocks2.length) {
           if (blocks2[j][0] == ch || blocks2[j][1] == ch) {
               if (blocks2.length > 1)
                   blocks2[j] = blocks2[$ - 1];
               blocks2 = blocks2[0 .. $ - 1];
               continue outer;
           }
       }
       return false;
   }
   return true;

}

void main() {

   import std.stdio, std.string;
   immutable blocks = "BO XK DQ CP NA GT RE TG QD FS JW HU VI
                       AN OB ER FS LY PC ZM".split;
   foreach (word; "" ~ "A BARK BoOK TrEAT COmMoN SQUAD conFUsE".split)
       writefln(`"%s" %s`, word, canMakeWord(word, blocks));

}</lang>

Recursive Version

This version is able to find the solution for the word "abba" given the blocks AB AB AC AC.

Translation of: C

<lang d>import std.stdio, std.ascii, std.algorithm, std.array;

alias Block = char[2];

// Modifies the order of the given blocks. bool canMakeWord(Block[] blocks, in string word) pure nothrow in {

   assert(blocks.all!(w => w[].all!isAlpha));
   assert(word.all!isAlpha);

} body {

   if (word.empty)
       return true;
   immutable c = word[0].toUpper;
   foreach (ref b; blocks) {
       if (b[0].toUpper != c && b[1].toUpper != c)
           continue;
       blocks[0].swap(b);
       if (blocks[1 .. $].canMakeWord(word[1 .. $]))
           return true;
       blocks[0].swap(b);
   }
   return false;

}

void main() {

   enum Block[] blocks = "BO XK DQ CP NA GT RE TG QD FS
                          JW HU VI AN OB ER FS LY PC ZM".split;
   foreach (w; "" ~ "A BARK BoOK TrEAT COmMoN SQUAD conFUsE".split)
       writefln(`"%s" %s`, w, blocks.canMakeWord(w));
   // Extra test.
   Block[] blocks2 = ["AB", "AB", "AC", "AC"];
   immutable word = "abba";
   writefln(`"%s" %s`, word, blocks2.canMakeWord(word));

}</lang>

Output:
"" true
"A" true
"BARK" true
"BoOK" false
"TrEAT" true
"COmMoN" false
"SQUAD" true
"conFUsE" true
"abba" true

Alternative Recursive Version

This version doesn't shuffle the input blocks, but it's more complex and it allocates an array of indexes. <lang d>import std.stdio, std.ascii, std.algorithm, std.array, std.range;

alias Block = char[2];

bool canMakeWord(immutable Block[] blocks, in string word) pure nothrow in {

   assert(blocks.all!(w => w[].all!isAlpha));
   assert(word.all!isAlpha);

} body {

   bool inner(size_t[] indexes, in string w) pure nothrow {
       if (w.empty)
           return true;
       immutable c = w[0].toUpper;
       foreach (ref idx; indexes) {
           if (blocks[idx][0].toUpper != c &&
               blocks[idx][1].toUpper != c)
               continue;
           indexes[0].swap(idx);
           if (inner(indexes[1 .. $], w[1 .. $]))
               return true;
           indexes[0].swap(idx);
       }
       return false;
   }
   return inner(blocks.length.iota.array, word);

}

void main() {

   enum Block[] blocks = "BO XK DQ CP NA GT RE TG QD FS
                          JW HU VI AN OB ER FS LY PC ZM".split;
   foreach (w; "" ~ "A BARK BoOK TrEAT COmMoN SQUAD conFUsE".split)
       writefln(`"%s" %s`, w, blocks.canMakeWord(w));
   // Extra test.
   immutable Block[] blocks2 = ["AB", "AB", "AC", "AC"];
   immutable word = "abba";
   writefln(`"%s" %s`, word, blocks2.canMakeWord(word));

}</lang> The output is the same.

Delphi

Just to be different I implemented a block as a set of (2) char rather than as an array of (2) char. <lang Delphi>program ABC; {$APPTYPE CONSOLE}

uses SysUtils;

type

 TBlock = set of char;

const

 TheBlocks : array [0..19] of TBlock =
 (
   [ 'B', 'O' ],    [ 'X', 'K' ],    [ 'D', 'Q' ],    [ 'C', 'P' ],    [ 'N', 'A' ],
   [ 'G', 'T' ],    [ 'R', 'E' ],    [ 'T', 'G' ],    [ 'Q', 'D' ],    [ 'F', 'S' ],
   [ 'J', 'W' ],    [ 'H', 'U' ],    [ 'V', 'I' ],    [ 'A', 'N' ],    [ 'O', 'B' ],
   [ 'E', 'R' ],    [ 'F', 'S' ],    [ 'L', 'Y' ],    [ 'P', 'C' ],    [ 'Z', 'M' ]
 );

function SolveABC(Target : string; Blocks : array of TBlock) : boolean; var

 iChr : integer;
 Used : array [0..19] of boolean;
 function FindUnused(TargetChr : char) : boolean;  // Nested routine
 var
   iBlock : integer;
 begin
   Result := FALSE;
   for iBlock := low(Blocks) to high(Blocks) do
     if (not Used[iBlock]) and ( TargetChr in Blocks[iBlock] ) then
     begin
       Result := TRUE;
       Used[iBlock] := TRUE;
       Break;
     end;
 end;

begin

 FillChar(Used, sizeof(Used), ord(FALSE));
 Result := TRUE;
 iChr := 1;
 while Result and (iChr <= length(Target)) do
   if FindUnused(Target[iChr]) then inc(iChr)
                               else Result := FALSE;

end;

procedure CheckABC(Target : string); begin

 if SolveABC(uppercase(Target), TheBlocks) then
   writeln('Can make ' + Target)
 else
   writeln('Can NOT make ' + Target);

end;

begin

 CheckABC('A');
 CheckABC('BARK');
 CheckABC('BOOK');
 CheckABC('TREAT');
 CheckABC('COMMON');
 CheckABC('SQUAD');
 CheckABC('CONFUSE');
 readln;

end. </lang>

Output:
Output:
Can make A
Can make BARK
Can NOT make BOOK
Can make TREAT
Can NOT make COMMON
Can make SQUAD
Can make CONFUSE

EchoLisp

<lang scheme> (lib 'list) ;; list-delete

(define BLOCKS '("BO" "XK" "DQ" "CP" "NA" "GT" "RE" "TG" "QD" "FS" "JW" "HU" "VI" "AN" "OB" "ER" "FS" "LY" "PC" "ZM" ))

(define WORDS '("A" "BARK" "BOOK" "TREAT" "COMMON" "SQUAD" "CONFUSE"))

(define (spell word blocks)

   (cond

((string-empty? word) #t) ((empty? blocks) #f) (else (for/or [(block blocks)] #:continue (not (string-match block (string-first word))) (spell (string-rest word) (list-delete blocks block))))))

</lang>

Output:
(for ((w WORDS)) 
  (writeln 
    (string-randcase w) 
    (spell (string-upcase w) BLOCKS)))
	
A     #t    
bARK     #t    
BooK     #f    
TReAt     #t    
ComMOn     #f    
sqUAd     #t    
COnfUSe     #t  

Ela

Translation of: Haskell

<lang ela>open list monad io char

IO

null = foldr (\_ _ -> false) true

mapM_ f = foldr ((>>-) << f) (return ())

abc _ [] = [[]] abc blocks (c::cs) =

 [b::ans \\ b <- blocks | c `elem` b, ans <- abc (delete b blocks) cs]

blocks = ["BO", "XK", "DQ", "CP", "NA", "GT", "RE", "TG", "QD", "FS",

         "JW", "HU", "VI", "AN", "OB", "ER", "FS", "LY", "PC", "ZM"]

mapM_ (\w -> putLn (w, not << null $ abc blocks (map char.upper w)))

 ["", "A", "BARK", "BoOK", "TrEAT", "COmMoN", "SQUAD", "conFUsE"]</lang>
Output:
("conFUsE",true)
("SQUAD",true)
("COmMoN",false)
("TrEAT",true)
("BoOK",false)
("BARK",true)
("A",true)
("",true)

Elena

ELENA 3.x <lang elena>#import system'routines.

  1. import system'collections.
  2. import extensions.
  3. import extensions'routines.

extension op {

   canMakeWord &from:blocks
   [
       var list := ArrayList new:blocks.

       ^ $nil == self literal upperCase seek &each:ch
       [
           var index := list indexOfElement:
               (word [ word indexOf:ch &at:0 != -1 ] asComparer).

           if (index>=0)
               [ list remove &at:index. ^ false. ];
               [ ^ true. ].
       ].
   ]

}

program = [

   var blocks := ("BO", "XK", "DQ", "CP", "NA", 

"GT", "RE", "TG", "QD", "FS", "JW", "HU", "VI", "AN", "OB", "ER", "FS", "LY", "PC", "ZM").

   var words := ("", "A", "BARK", "BOOK", "TREAT", "COMMON", "SQUAD", "Confuse").  

   words run &each:word
   [
       console writeLine:"can make '":word:"' : ":(word canMakeWord &from:blocks).
   ].

].</lang>

Output:
can make '' : true
can make 'A' : true
can make 'BARK' : true
can make 'BOOK' : false
can make 'TREAT' : true
can make 'COMMON' : false
can make 'SQUAD' : true
can make 'Confuse' : true

Elixir

Translation of: Erlang
Works with: Elixir version 1.3

<lang elixir>defmodule ABC do

 def can_make_word(word, avail) do
   can_make_word(String.upcase(word) |> to_charlist, avail, [])
 end
 
 defp can_make_word([], _, _), do: true
 defp can_make_word(_, [], _), do: false
 defp can_make_word([l|tail], [b|rest], tried) do 
   (l in b and can_make_word(tail, rest++tried, []))
   or can_make_word([l|tail], rest, [b|tried])
 end

end

blocks = ~w(BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM)c ~w(A Bark Book Treat Common Squad Confuse) |> Enum.map(fn(w) -> IO.puts "#{w}: #{ABC.can_make_word(w, blocks)}" end)</lang>

Output:
A: true
Bark: true
Book: false
Treat: true
Common: false
Squad: true
Confuse: true

Erlang

<lang erlang>-module(abc). -export([can_make_word/1, can_make_word/2, blocks/0]).

blocks() -> ["BO", "XK", "DQ", "CP", "NA", "GT", "RE", "TG", "QD", "FS",

            "JW", "HU", "VI", "AN", "OB", "ER", "FS", "LY", "PC", "ZM"].

can_make_word(Word) -> can_make_word(Word, blocks()). can_make_word(Word, Avail) -> can_make_word(string:to_upper(Word), Avail, []). can_make_word([], _, _) -> true; can_make_word(_, [], _) -> false; can_make_word([L|Tail], [B|Rest], Tried) ->

 (lists:member(L,B) andalso can_make_word(Tail, lists:append(Rest, Tried),[])) 
 orelse can_make_word([L|Tail], Rest, [B|Tried]).

main(_) -> lists:map(fun(W) -> io:fwrite("~s: ~s~n", [W, can_make_word(W)]) end,

                    ["A","Bark","Book","Treat","Common","Squad","Confuse"]).

</lang>

Output:
A: true
Bark: true
Book: false
Treat: true
Common: false
Squad: true
Confuse: true

ERRE

<lang ERRE> PROGRAM BLOCKS

!$INCLUDE="PC.LIB"

PROCEDURE CANMAKEWORD(WORD$)

  LOCAL B$,P%
  B$=BLOCKS$
  PRINT(WORD$;" -> ";)
  P%=INSTR(B$,CHR$(ASC(WORD$) AND $DF))
  WHILE P%>0 AND WORD$>"" DO
     CHANGE(B$,P%-1+(P% MOD 2),".."->B$)
     WORD$=MID$(WORD$,2)
     EXIT IF WORD$=""
     P%=INSTR(B$,CHR$(ASC(WORD$) AND $DF))
  END WHILE
  IF WORD$>"" THEN PRINT("False") ELSE PRINT("True") END IF

END PROCEDURE

BEGIN

 BLOCKS$="BOXKDQCPNAGTRETGQDFSJWHUVIANOBERFSLYPCZM"
 CANMAKEWORD("A")
 CANMAKEWORD("BARK")
 CANMAKEWORD("BOOK")
 CANMAKEWORD("TREAT")
 CANMAKEWORD("COMMON")
 CANMAKEWORD("SQUAD")
 CANMAKEWORD("Confuse")

END PROGRAM </lang>

Euphoria

implemented using OpenEuphoria <lang Euphoria> include std/text.e

sequence blocks = {{'B','O'},{'X','K'},{'D','Q'},{'C','P'},{'N','A'},

                  {'G','T'},{'R','E'},{'T','G'},{'Q','D'},{'F','S'},
                  {'J','W'},{'H','U'},{'V','I'},{'A','N'},{'O','B'},
                  {'E','R'},{'F','S'},{'L','Y'},{'P','C'},{'Z','M'}}

sequence words = {"A","BarK","BOOK","TrEaT","COMMON","SQUAD","CONFUSE"}

sequence current_word sequence temp integer matches

for i = 1 to length(words) do current_word = upper(words[i]) temp = blocks matches = 0 for j = 1 to length(current_word) do for k = 1 to length(temp) do if find(current_word[j],temp[k]) then temp = remove(temp,k) matches += 1 exit end if end for if length(current_word) = matches then printf(1,"%s: TRUE\n",{words[i]}) exit end if end for if length(current_word) != matches then printf(1,"%s: FALSE\n",{words[i]}) end if end for

if getc(0) then end if </lang>

Output:
A: TRUE
BarK: TRUE
BOOK: FALSE
TrEaT: TRUE
COMMON: FALSE
SQUAD: TRUE
CONFUSE: TRUE

..press Enter..

F#

This solution does not depend on the order of the blocks, neither on the symmetry of blocks we see in the example block set. (Symmetry: if AB is a block, an A comes only with another AB|BA)

<lang fsharp>let rec spell_word_with blocks w =

   let rec look_for_right_candidate candidates noCandidates c rest =
       match candidates with
       | [] -> false
       | c0::cc -> 
           if spell_word_with (cc@noCandidates) rest then true
           else look_for_right_candidate cc (c0::noCandidates) c rest
   match w with
   | "" -> true
   | w ->
       let c = w.[0]
       let rest = w.Substring(1)
       let (candidates, noCandidates) = List.partition(fun (c1,c2) -> c = c1 || c = c2) blocks
       look_for_right_candidate candidates noCandidates c rest

[<EntryPoint>] let main argv =

   let default_blocks = "BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM"
   let blocks =
       (if argv.Length > 0 then argv.[0] else default_blocks).Split()
       |> List.ofArray
       |> List.map(fun s -> s.ToUpper())
       |> List.map(fun s2 -> s2.[0], s2.[1])
   let words =
       (if argv.Length > 0 then List.ofArray(argv).Tail else [])
       |> List.map(fun s -> s.ToUpper())
   List.iter (fun w -> printfn "Using the blocks we can make the word '%s': %b" w (spell_word_with blocks w)) words
   0</lang>
Output:
h:\RosettaCode\ABC\Fsharp>RosettaCode "BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM" a bark book threat common squad confuse
Using the blocks we can make the word 'A': true
Using the blocks we can make the word 'BARK': true
Using the blocks we can make the word 'BOOK': false
Using the blocks we can make the word 'THREAT': true
Using the blocks we can make the word 'COMMON': false
Using the blocks we can make the word 'SQUAD': true
Using the blocks we can make the word 'CONFUSE': true

h:\RosettaCode\ABC\Fsharp>RosettaCode  "aB aB Ac Ac" abba
Using the blocks we can make the word 'ABBA': true

h:\RosettaCode\ABC\Fsharp>RosettaCode "US TZ AO QA" Auto
Using the blocks we can make the word 'AUTO': true

FBSL

This approach uses a string, blanking out the pair previously found. Probably faster than array manipulation. <lang qbasic>

  1. APPTYPE CONSOLE

SUB MAIN() BlockCheck("A") BlockCheck("BARK") BlockCheck("BooK") BlockCheck("TrEaT") BlockCheck("comMON") BlockCheck("sQuAd") BlockCheck("Confuse") pause END SUB

FUNCTION BlockCheck(str) print str " " iif( Blockable( str ), "can", "cannot" ) " be spelled with blocks." END FUNCTION

FUNCTION Blockable(str AS STRING) DIM blocks AS STRING = "BOXKDQCPNAGTRETGQDFSJWHUVIANOBERFSLYPCZM" DIM C AS STRING = "" DIM POS AS INTEGER = 0

FOR DIM I = 1 TO LEN(str) C = str{i} POS = INSTR(BLOCKS, C, 0, 1) 'case insensitive IF POS > 0 THEN 'if the pos is odd, it's the first of the pair IF POS MOD 2 = 1 THEN 'so clear the first and the second poke(@blocks + pos - 1," ") poke(@blocks + pos," ") 'otherwise, it's the last of the pair ELSE 'clear the second and the first poke(@blocks + pos - 1," ") poke(@blocks + pos - 2," ") END IF ELSE 'not found, so can't be spelled RETURN FALSE END IF NEXT 'got thru to here, so can be spelled RETURN TRUE END FUNCTION </lang>

Output:
A can be spelled with blocks.
BARK can be spelled with blocks.
BooK cannot be spelled with blocks.
TrEaT can be spelled with blocks.
comMON cannot be spelled with blocks.
sQuAd can be spelled with blocks.
Confuse can be spelled with blocks.

Press any key to continue...

Fortran

Attempts to write the word read from unit 5. Please find the output, bash command, and gfortran compilation instructions as commentary at the start of the source, which starts right away! <lang Fortran>!-*- mode: compilation; default-directory: "/tmp/" -*- !Compilation started at Thu Jun 5 01:52:03 ! !make f && for a in a bark book treat common squad confuse ; do echo $a | ./f ; done !gfortran -std=f2008 -Wall -fopenmp -ffree-form -fall-intrinsics -fimplicit-none -g f.f08 -o f ! T ! T A NA ! T BARK BO NA RE XK ! F BOOK OB BO -- -- ! T TREAT GT RE ER NA TG ! F COMMON PC OB ZM -- -- -- ! T SQUAD FS DQ HU NA QD ! T CONFUSE CP BO NA FS HU FS RE ! !Compilation finished at Thu Jun 5 01:52:03

program abc

 implicit none
 integer, parameter :: nblocks = 20
 character(len=nblocks) :: goal
 integer, dimension(nblocks) :: solution
 character(len=2), dimension(0:nblocks) :: blocks_copy, blocks = &
      &(/'--','BO','XK','DQ','CP','NA','GT','RE','TG','QD','FS','JW','HU','VI','AN','OB','ER','FS','LY','PC','ZM'/)
 logical :: valid
 integer :: i, iostat
 read(5,*,iostat=iostat) goal
 if (iostat .ne. 0) goal = 
 call ucase(goal)
 solution = 0
 blocks_copy = blocks
 valid = assign_block(goal(1:len_trim(goal)), blocks, solution, 1)
 write(6,*) valid, ' '//goal, (' '//blocks_copy(solution(i)), i=1,len_trim(goal))

contains

 recursive function assign_block(goal, blocks, solution, n) result(valid)
   implicit none
   logical :: valid
   character(len=*), intent(in) :: goal
   character(len=2), dimension(0:), intent(inout) :: blocks
   integer, dimension(:), intent(out) :: solution
   integer, intent(in) :: n
   integer :: i
   character(len=2) :: backing_store
   valid = .true.
   if (len(goal)+1 .eq. n) return
   do i=1, size(blocks)
      if (index(blocks(i),goal(n:n)) .ne. 0) then
         backing_store = blocks(i)
         blocks(i) = 
         solution(n) = i
         if (assign_block(goal, blocks, solution, n+1)) return
         blocks(i) = backing_store
      end if
   end do
   valid = .false.
   return
 end function assign_block
 subroutine ucase(a)
   implicit none
   character(len=*), intent(inout) :: a
   integer :: i, j
   do i = 1, len_trim(a)
      j = index('abcdefghijklmnopqrstuvwxyz',a(i:i))
      if (j .ne. 0) a(i:i) = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'(j:j)
   end do
 end subroutine ucase

end program abc</lang>

But if backtracking might be needed

The example set does not exercise the possible need for backtracking, as when an initial selection of blocks prevents completion because available letters have been used up. This can only arise when the same letter appears on more than one block and does so with different partners. The example set does contain duplicated letters, but they appear only via blocks with the same letters. Suppose instead that the block collection was AB, BC, CD, ... XY, YZ so that every letter appears twice except for A and Z. If the target word was STOPPED then both OP and PQ would be needed to supply P, but if the O had been supplied via OP then the second P would be unavailable. If instead the O were to be supplied by NO then all would be well.

The method involves the stack-style usage of array MOVE, but there is no explicit attempt at recursion. The array contains the possible moves at each level, and if necessary, a move made can later be retracted and an alternative sought. This is the standard style of playing board games such as chess via developing a "game tree", but in this case the tree traversal is not a large task.

The following source begins with some support routines. Subroutine PLAY inspects the collection of blocks to make various remarks, and function CANBLOCK reports on whether a word can be spelled out with the supplied blocks. The source requires only a few of the F90 features. The MODULE protocol eases communication, but the key feature is that subprograms can now declare arrays of a size determined on entry via parameters. Previously, a constant with the largest-possible size would be required. <lang Fortran>

     MODULE PLAYPEN	!Messes with a set of alphabet blocks.
      INTEGER MSG		!Output unit number.
      PARAMETER (MSG = 6)	!Standard output.
      INTEGER MS		!I dislike unidentified constants...
      PARAMETER (MS = 2)	!So this is the maximum number of lettered sides.
      INTEGER LETTER(26),SUPPLY(26)	!For counting the alphabet.
      CONTAINS
       SUBROUTINE SWAP(I,J)	!This really should be known to the compiler.
        INTEGER I,J,K		!Which could generate in-place code,
         K = I			!Using registers, maybe.
         I = J			!Or maybe, there are special op-codes.
         J = K			!Rather than this clunkiness.
       END SUBROUTINE SWAP	!And it should be for any type of thingy.
       INTEGER FUNCTION LSTNB(TEXT)  !Sigh. Last Not Blank.

Concocted yet again by R.N.McLean (whom God preserve) December MM. Code checking reveals that the Compaq compiler generates a copy of the string and then finds the length of that when using the latter-day intrinsic LEN_TRIM. Madness! Can't DO WHILE (L.GT.0 .AND. TEXT(L:L).LE.' ') !Control chars. regarded as spaces. Curse the morons who think it good that the compiler MIGHT evaluate logical expressions fully. Crude GO TO rather than a DO-loop, because compilers use a loop counter as well as updating the index variable. Comparison runs of GNASH showed a saving of ~3% in its mass-data reading through the avoidance of DO in LSTNB alone. Crappy code for character comparison of varying lengths is avoided by using ICHAR which is for single characters only. Checking the indexing of CHARACTER variables for bounds evoked astounding stupidities, such as calculating the length of TEXT(L:L) by subtracting L from L! Comparison runs of GNASH showed a saving of ~25-30% in its mass data scanning for this, involving all its two-dozen or so single-character comparisons, not just in LSTNB.

        CHARACTER*(*),INTENT(IN):: TEXT	!The bumf. If there must be copy-in, at least there need not be copy back.
        INTEGER L		!The length of the bumf.
         L = LEN(TEXT)		!So, what is it?
   1     IF (L.LE.0) GO TO 2	!Are we there yet?
         IF (ICHAR(TEXT(L:L)).GT.ICHAR(" ")) GO TO 2	!Control chars are regarded as spaces also.
         L = L - 1		!Step back one.
         GO TO 1		!And try again.
   2     LSTNB = L		!The last non-blank, possibly zero.
        RETURN			!Unsafe to use LSTNB as a variable.
       END FUNCTION LSTNB	!Compilers can bungle it.
       SUBROUTINE LETTERCOUNT(TEXT)	!Count the occurrences of A-Z.
        CHARACTER*(*) TEXT	!The text to inspect.
        INTEGER I,K		!Assistants.
         DO I = 1,LEN(TEXT)		!Step through the text.
           K = ICHAR(TEXT(I:I)) - ICHAR("A") + 1	!This presumes that A-Z have contiguous codes!
           IF (K.GE.1 .AND. K.LE.26) LETTER(K) = LETTER(K) + 1	!Not so with EBCDIC!!
         END DO			!On to the next letter.
       END SUBROUTINE LETTERCOUNT	!Be careful with LETTER.
       SUBROUTINE UPCASE(TEXT)	!In the absence of an intrinsic...

Converts any lower case letters in TEXT to upper case... Concocted yet again by R.N.McLean (whom God preserve) December MM. Converting from a DO loop evades having both an iteration counter to decrement and an index variable to adjust.

        CHARACTER*(*) TEXT	!The stuff to be modified.

c CHARACTER*26 LOWER,UPPER !Tables. a-z may not be contiguous codes. c PARAMETER (LOWER = "abcdefghijklmnopqrstuvwxyz") c PARAMETER (UPPER = "ABCDEFGHIJKLMNOPQRSTUVWXYZ") CAREFUL!! The below relies on a-z and A-Z being contiguous, as is NOT the case with EBCDIC.

        INTEGER I,L,IT		!Fingers.
         L = LEN(TEXT)		!Get a local value, in case LEN engages in oddities.
         I = L			!Start at the end and work back..
   1     IF (I.LE.0) RETURN 	!Are we there yet? Comparison against zero should not require a subtraction.

c IT = INDEX(LOWER,TEXT(I:I)) !Well? c IF (IT .GT. 0) TEXT(I:I) = UPPER(IT:IT) !One to convert?

         IT = ICHAR(TEXT(I:I)) - ICHAR("a")		!More symbols precede "a" than "A".
         IF (IT.GE.0 .AND. IT.LE.25) TEXT(I:I) = CHAR(IT + ICHAR("A"))	!In a-z? Convert!
         I = I - 1			!Back one.
         GO TO 1			!Inspect..
       END SUBROUTINE UPCASE	!Easy.
       SUBROUTINE ORDERSIDE(LETTER)	!Puts the letters into order.
        CHARACTER*(*) LETTER	!The letters.
        INTEGER I,N,H		!Assistants.
        CHARACTER*1 T		!A scratchpad.
        LOGICAL CURSE		!A bit.
         N = LEN(LETTER)	!So, how many letters?
         H = N - 1		!Last - First, and not +1.
         IF (H.LE.0) RETURN	!Ha ha.
   1     H = MAX(1,H*10/13)		!The special feature.
         IF (H.EQ.9 .OR. H.EQ.10) H = 11	!A twiddle.
         CURSE = .FALSE.		!So far, so good.
         DO I = N - H,1,-1		!If H = 1, this is a BubbleSort.
           IF (LETTER(I:I).LT.LETTER(I + H:I + H)) THEN	!One compare.
             T = LETTER(I:I)			!One swap.
             LETTER(I:I) = LETTER(I + H:I + H)	!Alas, no SWAP(A,B)
             LETTER(I + H:I + H) = T		!Is recognised by the compiler.
             CURSE = .TRUE.		!If once a tiger is seen...
           END IF			!So much for that comparison.
         END DO			!On to the next.
         IF (CURSE .OR. H.GT.1) GO TO 1!Another pass?
       END SUBROUTINE ORDERSIDE	!Simple enough.
       SUBROUTINE ORDERBLOCKS(N,SOME)	!Puts the collection of blocks into order.
        INTEGER N		!The number of blocks.
        CHARACTER*(*) SOME(:)	!Their lists of letters.
        INTEGER I,H		!Assistants.
        CHARACTER*(LEN(SOME(1))) T	!A scratchpad matching an element of SOME.
        LOGICAL CURSE			!Since there is still no SWAP(SOME(I),SOME(I + H)).
         H = N - 1		!So here comes another CombSort.
         IF (H.LE.0) RETURN	!With standard suspicion.
   1     H = MAX(1,H*10/13)		!This is the outer loop.
         IF (H.EQ.9 .OR. H.EQ.10) H = 11	!This is a fiddle.
         CURSE = .FALSE.		!Start the next pass in hope.
         DO I = N - H,1,-1		!Going backwards, just for fun.
           IF (SOME(I).LT.SOME(I + H)) THEN	!So then?
             T = SOME(I)		!Disorder.
             SOME(I) = SOME(I + H)	!So once again,
             SOME(I + H) = T		!Swap the two miscreants.
             CURSE = .TRUE.		!And remember.
           END IF			!So much for that comparison.
         END DO			!On to the next.
         IF (CURSE .OR. H.GT.1) GO TO 1!Are we there yet?
       END SUBROUTINE ORDERBLOCKS	!Not much code, but ringing the changes is still tedious.
       SUBROUTINE PLAY(N,SOME)	!Mess about with the collection of blocks.
        INTEGER N		!Their number.
        CHARACTER*(*) SOME(:)	!Their letters.
        INTEGER NH,HIT(N)	!A list of blocks.
        INTEGER B,I,J,K,L,M	!Assistants.
        CHARACTER*1 C		!A letter of the moment.
         L = LEN(SOME(1))	!The maximum number of letters to any block.

Cast the collection on to the floor.

         WRITE (MSG,1) N,L,SOME	!Announce the set as it is supplied.
   1     FORMAT (I7," blocks, with at most",I2," letters:",66(1X,A))

Change the "orientation" of some blocks.

         DO B = 1,N		!Step through each block.
           CALL UPCASE(SOME(B))	!Paranoia rules.
           CALL ORDERSIDE(SOME(B))	!Put its letter list into order.
         END DO		!On to the next block.
         WRITE (MSG,2) SOME	!Reveal the orderly array.
   2     FORMAT (6X,"... the letters in reverse order:",66(1X,A))

Collate the collection of blocks.

         CALL ORDERBLOCKS(N,SOME)	!Now order the blocks by their letters.
         WRITE (MSG,3) SOME		!Reveal them in neato order.
   3     FORMAT (7X,"... the blocks in reverse order:",66(1X,A))

Count the appearances of the letters of the alphabet.

         LETTER = 0		!Enough of shuffling blocks around.
         DO B = 1,N		!Now inspect their collective letters.
           CALL LETTERCOUNT(SOME(B))	!A block's worth at a go.
         END DO		!On to the next block.
         SUPPLY = LETTER	!Save the counts of supplied letters.
         WRITE (MSG,4) (CHAR(ICHAR("A") + I - 1),I = 1,26),SUPPLY	!Results.
   4     FORMAT (15X,"Letters of the alphabet:",26A<MS + 1>,/,	!First, a line with A ... Z.
    1     11X,"... number thereof supplied:",26I<MS + 1>)	!Then a line of the associated counts.

Check for blocks with duplicated letters.

         WRITE (MSG,5)		!Announce.
   5     FORMAT (8X,"Blocks with duplicated letters:",$)	!Further output impends.
         M = 0			!No duplication found.
         DO B = 1,N		!So step through each block.
        JJ:DO J = 2,L			!Inspecting successive letters of the block,
             IF (SOME(B)(J:J).LE." ") EXIT JJ	!Provided they've not run out.
             DO K = 1,J - 1			!To see if it has appeared earlier.
               IF (SOME(B)(K:K).LE." ") EXIT JJ!Reverse order means that spaces will be at the end!
               IF (SOME(B)(J:J).EQ.SOME(B)(K:K)) THEN	!Well?
                 M = M + 1		!A match!
                 WRITE (MSG,6) SOME(B)	!Name the block.
   6             FORMAT (1X,A,$)	!With further output still impending,
                 EXIT JJ		!And give up on this block.
               END IF			!One duplicated letter is sufficient for its downfall.
             END DO			!Next letter up.
           END DO JJ			!On to the next letter of the block.
         END DO		!On to the next block.
         CALL HIC(M)		!Show the count and end the line.

Check for duplicate blocks, knowing that the array of blocks is ordered.

         WRITE (MSG,7)		!Announce.
   7     FORMAT (21X,"Duplicated blocks:",$)	!Again, leave the line dangling.
         K = 0			!No duplication found.
         B = 1			!Syncopation.
  70     B = B + 1		!Advance one.
         IF (B.GT.N) GO TO 72	!Are we there yet?
         IF (SOME(B).NE.SOME(B - 1)) GO TO 70	!No match? Search on.
         K = K + 1		!A match is counted.
         WRITE (MSG,6) SOME(B)	!Name it.
  71     B = B + 1		!And speed through continued matching.
         IF (B.GT.N) GO TO 72	!Unless we're of the end.
         IF (SOME(B).EQ.SOME(B - 1)) GO TO 71	!Continued matching?
         GO TO 70		!Mismatch: resume the normal scan.
  72     CALL HIC(K)		!So much for that.

Check for duplicated letters across different blocks.

         IF (ALL(SUPPLY.LE.1)) RETURN	!Unless there are no duplicated letters.
         WRITE (MSG,8)		!Announce.
   8     FORMAT ("Duplicated letters on different blocks:",$)	!More to come.
         K = 0		!Start another count.
         DO I = 1,26		!A well-known span.
           IF (SUPPLY(I).LE.1) CYCLE	!Any duplicated letters?
           C = CHAR(ICHAR("A") + I - 1)!Yes. This is the character.
           NH = 0		!So, how many blocks contribute?
           DO B = 1,N		!Find out.
             IF (INDEX(SOME(B),C).GT.0) THEN	!On this block?
               NH = NH + 1		!Yes.
               HIT(NH) = B		!Keep track of which.
             END IF			!So much for that block.
           END DO		!On to the next.
           IF (ANY(SOME(HIT(2:NH)) .NE. SOME(HIT(1)))) THEN	!All have the same collection of letters?
             K = K + 1			!No!
             WRITE (MSG,9) C		!Name the heterogenously supported letter.
   9         FORMAT (A<MS + 1>,$)	!Use the same spacing even though one character only.
           END IF		!So much for that letter's search.
         END DO		!On to the next letter.
         CALL HIC(K)	!Finish the line with the count report.
        CONTAINS	!This is used often enough.
         SUBROUTINE HIC(N)	!But has very specific context.
          INTEGER N			!The count.
           IF (N.LE.0) WRITE (MSG,*) "None."	!Yes, we have no bananas.
           IF (N.GT.0) WRITE (MSG,*) N		!Either way, end the line.
         END SUBROUTINE HIC	!This service routine is not needed elsewhere.
       END SUBROUTINE PLAY	!Look mummy! All the blockses are neatened!
       LOGICAL FUNCTION CANBLOCK(WORD,N,SOME)	!Can the blocks spell out the word?

Creates a move tree based on the letters of WORD and for each, the blocks available.

        CHARACTER*(*) WORD	!The word to spell out.
        INTEGER N		!The number of blocks.
        CHARACTER*(*) SOME(:)	!The blocks and their letters.
        INTEGER NA,AVAIL(N)	!Say not the struggle naught availeth!
        INTEGER NMOVE(LEN(WORD))	!I need a list of acceptable blocks,
        INTEGER MOVE(LEN(WORD),N)	!One list for each letter of WORD.
        INTEGER I,L,S		!Assistants.
        CHARACTER*1 C		!The letter of the moment.
         CANBLOCK = .FALSE.		!Initial pessimism.
         L = LSTNB(WORD)		!Ignore trailing spaces.
         IF (L.GT.N) RETURN		!Enough blocks?
         LETTER = 0				!To make rabbit stew,
         CALL LETTERCOUNT(WORD(1:L))		!First catch your rabbit.
         IF (ANY(SUPPLY .LT. LETTER)) RETURN	!The larder is lacking.
         NA = N			!Prepare a list.
         FORALL (I = 1:N) AVAIL(I) = I	!That fingers every block.
         I = 0		!Step through the letters of the WORD.

Chug through the letters of the WORD.

   1     I = I + 1	!One letter after the other.
         IF (I.GT.L) GO TO 100	!Yay! We're through!
         C = WORD(I:I)		!The letter of the moment.
         NMOVE(I) = 0		!No moves known at this new level.
         DO S = 1,NA		!So, look for them amongst the available slots.
           IF (INDEX(SOME(AVAIL(S)),C) .GT. 0) THEN	!A hit?
             NMOVE(I) = NMOVE(I) + 1	!Yes! Count up another possible move.
             MOVE(I,NMOVE(I)) = S	!Remember its slot.
           END IF			!So much for that block.
         END DO		!On to the next.
   2     IF (NMOVE(I).GT.0) THEN	!Have we any moves?
           S = MOVE(I,NMOVE(I))	!Yes! Recover the last found.
           NMOVE(I) = NMOVE(I) - 1	!Uncount, as it is about to be used.
           IF (S.NE.NA) CALL SWAP(AVAIL(S),AVAIL(NA))	!This block is no longer available.
           NA = NA - 1			!Shift the boundary back.
           GO TO 1			!Try the next letter!
         END IF		!But if we can't find a move at that level...
         I = I - 1		!Retreat a level.
         IF (I.LE.0) RETURN	!Oh dear!
         S = MOVE(I,NMOVE(I) + 1)	!Undo the move that had been made at this level.
         NA = NA + 1			!And make its block is re-available.
         IF (S.NE.NA) CALL SWAP(AVAIL(S),AVAIL(NA))	!Move it back.
         GO TO 2		!See what moves remain at this level.

Completed!

 100     CANBLOCK = .TRUE.	!That's a relief.
       END FUNCTION CANBLOCK	!Some revisions might have been made.
     END MODULE PLAYPEN	!No sand here.
     USE PLAYPEN	!Just so.
     INTEGER HAVE,TESTS		!Parameters for the specified problem.
     PARAMETER (HAVE = 20, TESTS = 7)	!Number of blocks, number of tests.
     CHARACTER*(MS) BLOCKS(HAVE)	!Have blocks, will juggle.
     DATA BLOCKS/"BO","XK","DQ","CP","NA","GT","RE","TG","QD","FS",	!The specified set
    1            "JW","HU","VI","AN","OB","ER","FS","LY","PC","ZM"/	!Of letter blocks.
     CHARACTER*8 WORD(TESTS)		!Now for the specified test words.
     LOGICAL ANS(TESTS),T,F		!And the given results.
     PARAMETER (T = .TRUE., F = .FALSE.)	!Enable a more compact specification.
     DATA WORD/"A","BARK","BOOK","TREAT","COMMON","SQUAD","CONFUSE"/	!So that these
     DATA  ANS/ T ,    T ,    F ,     T ,      F ,     T ,       T /	!Can be aligned.
     LOGICAL YAY
     INTEGER I
     WRITE (MSG,1)
   1 FORMAT ("Arranges alphabet blocks, attending only to the ",
    1 "letters on the blocks, and ignoring case and orientation.",/)
     CALL PLAY(HAVE,BLOCKS)	!Some fun first.
     WRITE (MSG,'(/"Now to see if some words can be spelled out.")')
     DO I = 1,TESTS
       CALL UPCASE(WORD(I))
       YAY = CANBLOCK(WORD(I),HAVE,BLOCKS)
       WRITE (MSG,*) YAY,ANS(I),YAY.EQ.ANS(I),WORD(I)
     END DO
     END

</lang> Output: the first column of T/F is the report from CANBLOCK, the second is the expected answer from the example, and the third is whether the two are in agreement.

Arranges alphabet blocks, attending only to the letters on the blocks, and ignoring case and orientation.

     20 blocks, with at most 2 letters: BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM
      ... the letters in reverse order: OB XK QD PC NA TG RE TG QD SF WJ UH VI NA OB RE SF YL PC ZM
       ... the blocks in reverse order: ZM YL XK WJ VI UH TG TG SF SF RE RE QD QD PC PC OB OB NA NA
               Letters of the alphabet:  A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z
           ... number thereof supplied:  2  2  2  2  2  2  2  1  1  1  1  1  1  2  2  2  2  2  2  2  1  1  1  1  1  1
        Blocks with duplicated letters: None.
                     Duplicated blocks: TG SF RE QD PC OB NA           7
Duplicated letters on different blocks: None.

Now to see if some words can be spelled out.
 T T T A
 T T T BARK
 F F T BOOK
 T T T TREAT
 F F T COMMON
 T T T SQUAD
 T T T CONFUSE

Go

<lang go>package main

import ( "fmt" "strings" )

func newSpeller(blocks string) func(string) bool { bl := strings.Fields(blocks) return func(word string) bool { return r(word, bl) } }

func r(word string, bl []string) bool { if word == "" { return true } c := word[0] | 32 for i, b := range bl { if c == b[0]|32 || c == b[1]|32 { bl[i], bl[0] = bl[0], b if r(word[1:], bl[1:]) == true { return true } bl[i], bl[0] = bl[0], bl[i] } } return false }

func main() { sp := newSpeller( "BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM") for _, word := range []string{ "A", "BARK", "BOOK", "TREAT", "COMMON", "SQUAD", "CONFUSE"} { fmt.Println(word, sp(word)) } }</lang>

Output:
A true
BARK true
BOOK false
TREAT true
COMMON false
SQUAD true
CONFUSE true

Groovy

Solution: <lang groovy>class ABCSolver {

   def blocks
   ABCSolver(blocks = []) { this.blocks = blocks }
   boolean canMakeWord(rawWord) {
       if (rawWord ==  || rawWord == null) { return true; }
       def word = rawWord.toUpperCase()
       def blocksLeft = [] + blocks
       word.every { letter -> blocksLeft.remove(blocksLeft.find { block -> block.contains(letter) }) }
   }

}</lang>

Test: <lang groovy>def a = new ABCSolver(["BO", "XK", "DQ", "CP", "NA", "GT", "RE", "TG", "QD", "FS",

                     "JW", "HU", "VI", "AN", "OB", "ER", "FS", "LY", "PC", "ZM"])

[, 'A', 'BARK', 'book', 'treat', 'COMMON', 'SQuAd', 'CONFUSE'].each {

   println "'${it}': ${a.canMakeWord(it)}"

}</lang>

Output:
'': true
'A': true
'BARK': true
'book': false
'treat': true
'COMMON': false
'SQuAd': true
'CONFUSE': true

Harbour

Harbour Project implements a cross-platform Clipper/xBase compiler. <lang visualfoxpro>PROCEDURE Main()

  LOCAL cStr
  FOR EACH cStr IN { "A", "BARK", "BooK", "TrEaT", "comMON", "sQuAd", "Confuse" }
     ? PadL( cStr, 10 ), iif( Blockable( cStr ), "can", "cannot" ), "be spelled with blocks."
  NEXT
  RETURN

STATIC FUNCTION Blockable( cStr )

  LOCAL blocks := { ;
     "BO", "XK", "DQ", "CP", "NA", "GT", "RE", "TG", "QD", "FS", ;
     "JW", "HU", "VI", "AN", "OB", "ER", "FS", "LY", "PC", "ZM" }
  LOCAL cFinal := ""
  LOCAL i, j
  cStr := Upper( cStr )
  FOR i := 1 TO Len( cStr )
     FOR EACH j IN blocks
        IF SubStr( cStr, i, 1 ) $ j
           cFinal += SubStr( cStr, i, 1 )
           j := ""
           EXIT
        ENDIF
     NEXT
  NEXT
  RETURN cFinal == cStr</lang>
Output:
         A can be spelled with blocks.
      BARK can be spelled with blocks.
      BooK cannot be spelled with blocks.
     TrEaT can be spelled with blocks.
    comMON cannot be spelled with blocks.
     sQuAd can be spelled with blocks.
   Confuse can be spelled with blocks.

Haskell

The following function returns a list of all the solutions. Since Haskell is lazy, testing whether the list is null will only do the minimal amount of work necessary to determine whether a solution exists. <lang haskell>import Data.List (delete) import Data.Char (toUpper)

-- returns list of all solutions, each solution being a list of blocks abc :: (Eq a) => a -> [a] -> [[[a]]] abc _ [] = [[]] abc blocks (c:cs) = [b:ans | b <- blocks, c `elem` b,

                            ans <- abc (delete b blocks) cs]

blocks = ["BO", "XK", "DQ", "CP", "NA", "GT", "RE", "TG", "QD", "FS",

         "JW", "HU", "VI", "AN", "OB", "ER", "FS", "LY", "PC", "ZM"]

main :: IO () main = mapM_ (\w -> print (w, not . null $ abc blocks (map toUpper w)))

        ["", "A", "BARK", "BoOK", "TrEAT", "COmMoN", "SQUAD", "conFUsE"]</lang>
Output:
("",True)
("A",True)
("BARK",True)
("BoOK",False)
("TrEAT",True)
("COmMoN",False)
("SQUAD",True)
("conFUsE",True)

Or, in terms of foldMap:

<lang haskell>import Data.List (delete) import Data.Char (toUpper)

-- Any block sequences found spellWith :: [(Char, Char)] -> String -> (Char, Char) spellWith _ [] = [[]] spellWith blocks (x:xs) =

 foldMap
   (\b ->
       if fst b == x || snd b == x
         then foldMap (return . (b :)) (spellWith (delete b blocks) xs)
         else [])
   blocks

blocks :: [(Char, Char)] blocks =

 (\[x, y] -> (x, y)) <$>
 words "BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM"

main :: IO () main =

 mapM_
   (print . ((,) <*>) (not . null . spellWith blocks . (toUpper <$>)))
   ["", "A", "BARK", "BoOK", "TrEAT", "COmMoN", "SQUAD", "conFUsE"]</lang>
Output:
("",True)
("A",True)
("BARK",True)
("BoOK",False)
("TrEAT",True)
("COmMoN",False)
("SQUAD",True)
("conFUsE",True)

Icon and Unicon

Translation of: C

Works in both languages: <lang unicon>procedure main(A)

   blocks := ["bo","xk","dq","cp","na","gt","re","tg","qd","fs",
              "jw","hu","vi","an","ob","er","fs","ly","pc","zm",&null]
   every write("\"",word := !A,"\" ",checkSpell(map(word),blocks)," with blocks.")

end

procedure checkSpell(w,blocks)

   blks := copy(blocks)
   w ? return if canMakeWord(blks) then "can be spelled"
                                   else "can not be spelled"

end

procedure canMakeWord(blks)

   c := move(1) | return
   if /blks[1] then fail
   every i := 1 to *blks do {
       if /blks[i] then (move(-1),fail)
       if c == !blks[i] then {  
           blks[1] :=: blks[i]
           if canMakeWord(blks[2:0]) then return
           blks[1] :=: blks[i]
           }
       }

end</lang>

Sample run:

->abc "" A BARK BOOK TREAT COMMON SQUAD CONFUSE
"" can be spelled with blocks.
"A" can be spelled with blocks.
"BARK" can be spelled with blocks.
"BOOK" can not be spelled with blocks.
"TREAT" can be spelled with blocks.
"COMMON" can not be spelled with blocks.
"SQUAD" can be spelled with blocks.
"CONFUSE" can be spelled with blocks.
->

J

Solution: <lang j>reduce=: verb define

 'rows cols'=. i.&.> $y
 for_c. cols do.
   r=. 1 i.~ c {"1 y             NB. row idx of first 1 in col
   if. r = #rows do. continue. end.
   y=. 0 (<((r+1)}.rows);c) } y  NB. zero rest of col
   y=. 0 (<(r;(c+1)}.cols)) } y  NB. zero rest of row
 end.

)

abc=: *./@(+./)@reduce@(e."1~ ,)&toupper :: 0:</lang> Examples: <lang j> Blocks=: ];._2 'BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM '

  ExampleWords=: <;._2 'A BaRK BOoK tREaT COmMOn SqUAD CoNfuSE '
  Blocks&abc &> ExampleWords

1 1 0 1 0 1 1

  require 'format/printf'
  '%10s  %s' printf (dquote ; 'FT' {~ Blocks&abc) &> ExampleWords
      "A"  T
   "BaRK"  T
   "BOoK"  F
  "tREaT"  T
 "COmMOn"  F
  "SqUAD"  T
"CoNfuSE"  T</lang>

Tacit version <lang j>delElem=: {~<@<@< uppc=:(-32*96&<*.123&>)&.(3&u:) reduc=: ] delElem 1 i.~e."0 1 forms=: (1 - -: (reduc L:0/ :: (a:"_)@(<"0@],<@[))&uppc) L:0</lang>

Output:
   (,.Blocks&forms) ExampleWords
┌───────┬─┐
│A      │1│
├───────┼─┤
│BaRK   │1│
├───────┼─┤
│BOoK   │0│
├───────┼─┤
│tREaT  │1│
├───────┼─┤
│COmMOn │0│
├───────┼─┤
│SqUAD  │1│
├───────┼─┤
│CoNfuSE│1│
└───────┴─┘

Alternative Implementation

Another approach might be:

<lang J>Blocks=: >;:'BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM ' ExampleWords=: ;: 'A BaRK BOoK tREaT COmMOn SqUAD CoNfuSE '

canform=:4 :0

 word=: toupper y
 need=: #/.~ word,word
 relevant=: (x +./@e."1 word) # x
 candidates=: word,"1>,{{relevant
 +./(((#need){. #/.~)"1 candidates) */ .>:need

)</lang>

Example use:

<lang J> Blocks canform 0{::ExampleWords 1

  Blocks canform 1{::ExampleWords

1

  Blocks canform 2{::ExampleWords

0

  Blocks canform 3{::ExampleWords

1

  Blocks canform 4{::ExampleWords

0

  Blocks canform 5{::ExampleWords

1

  Blocks canform 6{::ExampleWords

1</lang>

Explanation:

We only need to consider blocks which contain letters in common with a normalized (upper case) version of the desired word. But we do need to consider all possible combinations of letters from those blocks (see talk page discussion of words like 'ABBA' for more on this issue).

We can classify possibilities by counting how many of each letter occur. If a candidate has at least as many of the required letters as a test case constructed from the word itself, it's a valid candidate.

For example:

<lang J> Blocks canform 0{::ExampleWords 1

  word

A

  need

2

  relevant

NA AN

  candidates

ANA ANN AAA AAN</lang>

Here, the word is simply 'A', and we have two blocks to consider for our word: AN and NA. So we form all possible combinations of the letters of those two bocks, prefix each of them with our word and test whether any of them contain two copies of the letters of our word. (As it happens, all of the candidates are valid, for this trivial example.)

Java

Translation of: D
Translation of: C
Works with: Java version 1.6+

<lang java5>import java.util.Arrays;

public class ABC{ private static void swap(int i, int j, Object... arr){ Object tmp = arr[i]; arr[i] = arr[j]; arr[j] = tmp; }

public static boolean canMakeWord(String word, String... blocks) { if(word.length() == 0) return true;

char c = Character.toUpperCase(word.charAt(0)); for(int i = 0; i < blocks.length; i++) { String b = blocks[i]; if(Character.toUpperCase(b.charAt(0)) != c && Character.toUpperCase(b.charAt(1)) != c) continue; swap(0, i, blocks); if(canMakeWord(word.substring(1), Arrays.copyOfRange(blocks, 1, blocks.length))) return true; swap(0, i, blocks); }

return false; }

public static void main(String[] args){ String[] blocks = {"BO", "XK", "DQ", "CP", "NA", "GT", "RE", "TG", "QD", "FS", "JW", "HU", "VI", "AN", "OB", "ER", "FS", "LY", "PC", "ZM"};

System.out.println("\"\": " + canMakeWord("", blocks)); System.out.println("A: " + canMakeWord("A", blocks)); System.out.println("BARK: " + canMakeWord("BARK", blocks)); System.out.println("book: " + canMakeWord("book", blocks)); System.out.println("treat: " + canMakeWord("treat", blocks)); System.out.println("COMMON: " + canMakeWord("COMMON", blocks)); System.out.println("SQuAd: " + canMakeWord("SQuAd", blocks)); System.out.println("CONFUSE: " + canMakeWord("CONFUSE", blocks));

} }</lang>

Output:
"": true
A: true
BARK: true
book: false
treat: true
COMMON: false
SQuAd: true
CONFUSE: true

JavaScript

ES5

Imperative

The following method uses regular expressions and the string replace function to allow more support for older browsers. <lang javascript>var blocks = "BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM";

function CheckWord(blocks, word) {

  // Makes sure that word only contains letters.
  if(word !== /([a-z]*)/i.exec(word)[1]) return false;
  // Loops through each character to see if a block exists.
  for(var i = 0; i < word.length; ++i)
  {
     // Gets the ith character.
     var letter = word.charAt(i);
     // Stores the length of the blocks to determine if a block was removed.
     var length = blocks.length;
     // The regexp gets constructed by eval to allow more browsers to use the function.
     var reg = eval("/([a-z]"+letter+"|"+letter+"[a-z])/i");
     // This does the same as above, but some browsers do not support...
     //var reg = new RegExp("([a-z]"+letter+"|"+letter+"[a-z])", "i");
     // Removes all occurrences of the match. 
     blocks = blocks.replace(reg, "");
     // If the length did not change then a block did not exist.
     if(blocks.length === length) return false;
  }
  // If every character has passed then return true.
  return true;

};

var words = [

  "A",
  "BARK", 
  "BOOK", 
  "TREAT", 
  "COMMON", 
  "SQUAD", 
  "CONFUSE" 

];

for(var i = 0;i<words.length;++i)

  console.log(words[i] + ": " + CheckWord(blocks, words[i]));

</lang>

Result:

A: true
BARK: true
BOOK: false
TREAT: true
COMMON: false
SQUAD: true
CONFUSE: true

Functional

<lang JavaScript>(function (strWords) {

   var strBlocks =
       'BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM',
       blocks = strBlocks.split(' ');
   function abc(lstBlocks, strWord) {
       var lngChars = strWord.length;
       if (!lngChars) return [];
       var b = lstBlocks[0],
           c = strWord[0];
       return chain(lstBlocks, function (b) {
           return (b.indexOf(c.toUpperCase()) !== -1) ? [
               (b + ' ').concat(
                   abc(removed(b, lstBlocks), strWord.slice(1)))
           ] : [];
       })
   }
   // Monadic bind (chain) for lists
   function chain(xs, f) {
       return [].concat.apply([], xs.map(f));
   }
   // a -> [a] -> [a]
   function removed(x, xs) {
       var h = xs.length ? xs[0] : null,
           t = h ? xs.slice(1) : [];
       return h ? (
           h === x ? t : [h].concat(removed(x, t))
       ) : [];
   }
   function solution(strWord) {
       var strAttempt = abc(blocks, strWord)[0].split(',')[0];
       // two chars per block plus one space -> 3
       return strWord + ((strAttempt.length === strWord.length * 3) ?
           ' -> ' + strAttempt : ': [no solution]');
   }
   return strWords.split(' ').map(solution).join('\n');

})('A bark BooK TReAT COMMON squAD conFUSE');</lang>

Output:

<lang JavaScript>A -> NA bark -> BO NA RE XK BooK: [no solution] TReAT -> GT RE ER NA TG COMMON: [no solution] squAD -> FS DQ HU NA QD conFUSE -> CP BO NA FS HU FS RE</lang>

ES6

Imperative

<lang javascript>let characters = "BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM"; let blocks = characters.split(" ").map(pair => pair.split(""));

function isWordPossible(word) {

 var letters = [...word.toUpperCase()];
 var length = letters.length;
 var copy = new Set(blocks);
 for (let letter of letters) {
   for (let block of copy) {
     let index = block.indexOf(letter);

     if (index !== -1) {
       length--;
       copy.delete(block);
       break;  
     }
   }
 }
 return !length;

}

[

 "A", 
 "BARK", 
 "BOOK", 
 "TREAT", 
 "COMMON", 
 "SQUAD", 
 "CONFUSE" 

].forEach(word => console.log(`${word}: ${isWordPossible(word)}`)); </lang>

Result:

A: true
BARK: true
BOOK: false
TREAT: true
COMMON: false
SQUAD: true
CONFUSE: true


Functional

Translation of: Haskell

<lang JavaScript>(() => {

   'use strict';
   // ABC BLOCKS -------------------------------------------------------------
   // spellWith :: [(Char, Char)] -> [Char] -> (Char, Char)
   const spellWith = (blocks, wordChars) => {
       if (isNull(wordChars)) {
           return [
               []
           ];
       } else {
           const [x, xs] = uncons(wordChars);
           return concatMap(
               b => elem(x, b) ? concatMap(
                   bs => [cons(b, bs)],
                   spellWith(
                       deleteBy(
                           (p, q) => (p[0] === q[0]) && (p[1] === q[1]),
                           b, blocks
                       ),
                       xs
                   )
               ) : [],
               blocks
           );
       }
   };
   // GENERIC FUNCTIONS ------------------------------------------------------
   // compose :: [(a -> a)] -> (a -> a)
   const compose = fs => x => fs.reduceRight((a, f) => f(a), x);
   // concatMap :: (a -> [b]) -> [a] -> [b]
   const concatMap = (f, xs) => [].concat.apply([], xs.map(f));
   // cons :: a -> [a] -> [a]
   const cons = (x, xs) => [x].concat(xs);
   // curry :: Function -> Function
   const curry = (f, ...args) => {
       const go = xs => xs.length >= f.length ? (f.apply(null, xs)) :
           function () {
               return go(xs.concat([].slice.apply(arguments)));
           };
       return go([].slice.call(args, 1));
   };
   // deleteBy :: (a -> a -> Bool) -> a -> [a] -> [a]
   const deleteBy = (f, x, xs) =>
       xs.length > 0 ? (
           f(x, xs[0]) ? (
               xs.slice(1)
           ) : [xs[0]].concat(deleteBy(f, x, xs.slice(1)))
       ) : [];
   // elem :: Eq a => a -> [a] -> Bool
   const elem = (x, xs) => xs.indexOf(x) !== -1;
   // isNull :: [a] -> Bool
   const isNull = xs => (xs instanceof Array) ? xs.length < 1 : undefined;
   // map :: (a -> b) -> [a] -> [b]
   const map = (f, xs) => xs.map(f);
   // not :: Bool -> Bool
   const not = b => !b;
   // show :: a -> String
   const show = x => JSON.stringify(x); //, null, 2);
   // stringChars :: String -> [Char]
   const stringChars = s => s.split();
   // toUpper :: Text -> Text
   const toUpper = s => s.toUpperCase();
   // uncons :: [a] -> Maybe (a, [a])
   const uncons = xs => xs.length ? [xs[0], xs.slice(1)] : undefined;
   // unlines :: [String] -> String
   const unlines = xs => xs.join('\n');
   // words :: String -> [String]
   const words = s => s.split(/\s+/);
   // TEST -------------------------------------------------------------------
   // blocks :: [(Char, Char)]
   const blocks = words(
       "BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM"
   );
   return unlines(map(
       x => show([x, compose(
           [not, isNull, curry(spellWith)(blocks), stringChars, toUpper]
       )(x)]), ["", "A", "BARK", "BoOK", "TrEAT", "COmMoN", "SQUAD", "conFUsE"]
   ));

})(); </lang>

Output:
["",true]
["A",true]
["BARK",true]
["BoOK",false]
["TrEAT",true]
["COmMoN",false]
["SQUAD",true]
["conFUsE",true]

jq

The problem description seems to imply that if a letter, X, appears on more than one block, its partner will be the same on all blocks. This makes the problem trivial.<lang jq>

  1. when_index(cond;ary) returns the index of the first element in ary
  2. that satisfies cond; it uses a helper function that takes advantage
  3. of tail-recursion optimization in recent versions of jq.

def index_when(cond; ary):

 # state variable: counter
 def when: if . >= (ary | length) then null
           elif ary[.] | cond then . 
           else (.+1) | when
           end;
 0 | when;
  1. Attempt to match a single letter with a block;
  2. return null if no match, else the remaining blocks

def match_letter(letter):

 . as $ary | index_when( index(letter); $ary ) as $ix
 | if $ix == null then null
   else del( .[$ix] )
   end;
  1. Usage: string | abc(blocks)

def abc(blocks):

 if length == 0 then true
 else
   .[0:1] as $letter
   | (blocks | match_letter( $letter )) as $blks
   | if $blks == null then false
     else .[1:] | abc($blks)
     end
 end;</lang>

Task:<lang jq>def task:

 ["BO","XK","DQ","CP","NA","GT","RE","TG","QD","FS",
  "JW","HU","VI","AN","OB","ER","FS","LY","PC","ZM"] as $blocks
 | ("A", "BARK","BOOK","TREAT","COMMON","SQUAD","CONFUSE")
 | "\(.) : \( .|abc($blocks) )" ;task</lang>
Output:
A : true
BARK : true
BOOK : false
TREAT : true
COMMON : false
SQUAD : true
CONFUSE : true

Julia

<lang Julia>function abc (str, list)

 isempty(str) && return true
 for i = eachindex(list)
   str[end] in list[i] && 
   any([abc(str[1:end-1], deleteat!(copy(list), i))]) &&
   return true
 end
 false

end</lang>

Output:
julia> let test = ["A", "BARK","BOOK","TREAT","COMMON","SQUAD","CONFUSE"],
           list = ["BO","XK","DQ","CP","NA","GT","RE","TG","QD","FS",
                     "JW","HU","VI","AN","OB","ER","FS","LY","PC","ZM"]
         for str in test
           @printf("%-8s |  %s\n", str, abc(str, list)) 
         end
       end
A        |  true
BARK     |  true
BOOK     |  false
TREAT    |  true
COMMON   |  false
SQUAD    |  true
CONFUSE  |  true

Kotlin

Translation of: Java

<lang scala>object ABC_block_checker {

   fun run() {
       val blocks = arrayOf("BO", "XK", "DQ", "CP", "NA", "GT", "RE", "TG", "QD", "FS",
               "JW", "HU", "VI", "AN", "OB", "ER", "FS", "LY", "PC", "ZM")
       println("\"\": " + blocks.canMakeWord(""))
       val words = arrayOf("A", "BARK", "book", "treat", "COMMON", "SQuAd", "CONFUSE")
       for (w in words)  println("$w: " + blocks.canMakeWord(w))
   }
   private fun Array<String>.swap(i: Int, j: Int) {
       val tmp = this[i]
       this[i] = this[j]
       this[j] = tmp
   }
   private fun Array<String>.canMakeWord(word: String): Boolean {
       if (word.isEmpty())
           return true
       val c = Character.toUpperCase(word.first())
       var i = 0
       forEach { b ->
           if (b.first().toUpperCase() == c || b[1].toUpperCase() == c) {
               swap(0, i)
               if (drop(1).toTypedArray().canMakeWord(word.substring(1)))
                   return true
               swap(0, i)
           }
           i++
       }
       return false
   }

}

fun main(args: Array<String>) = ABC_block_checker.run()</lang>

Output:
"": true
A: true
BARK: true
book: false
treat: true
COMMON: false
SQuAd: true
CONFUSE: true

Liberty BASIC

Recursive solution

<lang lb> print "Rosetta Code - ABC problem (recursive solution)" print blocks$="BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM" data "A" data "BARK", "BOOK", "TREAT", "COMMON", "SQUAD", "CONFUSE" data "XYZZY"

do

   read text$
   if text$="XYZZY" then exit do
   print ">>> can_make_word("; chr$(34); text$; chr$(34); ")"
   if canDo(text$,blocks$) then print "True" else print "False"

loop while 1 print "Program complete." end

function canDo(text$,blocks$)

   'endcase
   if len(text$)=1 then canDo=(instr(blocks$,text$)<>0): exit function
   'get next letter
   ltr$=left$(text$,1)
   'cut
   if instr(blocks$,ltr$)=0 then canDo=0: exit function
   'recursion
   text$=mid$(text$,2) 'rest
   'loop by all word in blocks. Need to make "newBlocks" - all but taken
   'optimisation: take only fitting blocks
   wrd$="*"
   i=0
   while wrd$<>""
       i=i+1
       wrd$=word$(blocks$, i)
       if instr(wrd$, ltr$) then
           'newblocks without wrd$
           pos=instr(blocks$,wrd$)
           newblocks$=left$(blocks$, pos-1)+mid$(blocks$, pos+3)
           canDo=canDo(text$,newblocks$)
           'first found cuts
           if canDo then exit while
       end if
   wend

end function </lang>

Output:
Rosetta Code - ABC problem (recursive solution)

>>> can_make_word("A")
True
>>> can_make_word("BARK")
True
>>> can_make_word("BOOK")
False
>>> can_make_word("TREAT")
True
>>> can_make_word("COMMON")
False
>>> can_make_word("SQUAD")
True
>>> can_make_word("CONFUSE")
True
Program complete.

Procedural solution

<lang lb> print "Rosetta Code - ABC problem (procedural solution)" print w$(1)="A" w$(2)="BARK" w$(3)="BOOK" w$(4)="TREAT" w$(5)="COMMON" w$(6)="SQUAD" w$(7)="CONFUSE"

for x=1 to 7

   print ">>> can_make_word("; chr$(34); w$(x); chr$(34); ")"
   if CanMakeWord(w$(x)) then print "True" else print "False"

next x print "Program complete." end

function CanMakeWord(x$) global DoneWithWord, BlocksUsed, LetterOK, Possibility dim block$(20,2), block(20,2) 'numeric blocks, col 0 flags used block block(1,1)=asc("B")-64: block(1,2)=asc("O")-64 block(2,1)=asc("X")-64: block(2,2)=asc("K")-64 block(3,1)=asc("D")-64: block(3,2)=asc("Q")-64 block(4,1)=asc("C")-64: block(4,2)=asc("P")-64 block(5,1)=asc("N")-64: block(5,2)=asc("A")-64 block(6,1)=asc("G")-64: block(6,2)=asc("T")-64 block(7,1)=asc("R")-64: block(7,2)=asc("E")-64 block(8,1)=asc("T")-64: block(8,2)=asc("G")-64 block(9,1)=asc("Q")-64: block(9,2)=asc("D")-64 block(10,1)=asc("F")-64: block(10,2)=asc("S")-64 block(11,1)=asc("J")-64: block(11,2)=asc("W")-64 block(12,1)=asc("H")-64: block(12,2)=asc("U")-64 block(13,1)=asc("V")-64: block(13,2)=asc("I")-64 block(14,1)=asc("A")-64: block(14,2)=asc("N")-64 block(15,1)=asc("O")-64: block(15,2)=asc("B")-64 block(16,1)=asc("E")-64: block(16,2)=asc("R")-64 block(17,1)=asc("F")-64: block(17,2)=asc("S")-64 block(18,1)=asc("L")-64: block(18,2)=asc("Y")-64 block(19,1)=asc("P")-64: block(19,2)=asc("C")-64 block(20,1)=asc("Z")-64: block(20,2)=asc("M")-64

x$=upper$(x$) for x=1 to len(x$)

   y$=mid$(x$,x,1)
   if y$>="A" and y$<="Z" then w$=w$+y$

next x if w$="" then exit function DoneWithWord=0: BlocksUsed=0 l=len(w$) dim LetterOK(l) dim alphabet(26,1) 'clear letter-usage array for x=1 to 20 'load block letters into letter-usage array col 0

   alphabet(block(x,1),0)+=1
   alphabet(block(x,2),0)+=1

next x for x=1 to l 'load current word into letter-usage aray col 1

   wl$=mid$(w$,x,1): w=asc(wl$)-64
   alphabet(w,1)+=1

next x

for x=1 to 26 ' test for more of any letter in the word than in the blocks

   if alphabet(x,1)>alphabet(x,0) then exit function

next x

[NextLetter] if wl<l then wl=wl+1 else goto [DoneWithWord] wl$=mid$(w$,wl,1): w=asc(wl$)-64 LetterOK=0 ' if there's only one of the letter in the blocks then you must use that block if alphabet(w,0)=1 then

   call OnlyBlock w
   LetterOK(wl)=1
   if DoneWithWord then goto [DoneWithWord] else goto [NextLetter]

end if ' if more than one of the letter in the blocks, then try to use one that has ' an unused letter on other side (a "Free Block") call FindFreeBlock w if LetterOK then LetterOK(wl)=1 goto [NextLetter]

[DoneWithWord] if BlocksUsed=l then CanMakeWord=1: exit function if DoneWithWord then exit function for x=1 to l

   if not(LetterOK(x)) then
       NumericLetter=asc(mid$(w$,x,1))-64
       LetterOK=0
       call OnlyBlock NumericLetter
       if LetterOK then LetterOK(x)=1 else exit for
   end if

next x goto [DoneWithWord] end function

sub OnlyBlock NumericLetter

   for x=1 to 20
       if (block(x, 1)=NumericLetter or block(x, 2)=NumericLetter) _
               and block(x, 0)=0 then
           call UseBlock x, NumericLetter
           exit sub
       end if
   next x
   DoneWithWord=1

end sub

sub FindFreeBlock NumericLetter

   Possibility=0
   for x=1 to 20
       if block(x, 0)=0 then 'block not used
           if block(x,1)=NumericLetter then
               if alphabet(block(x,2),1)=0 then
                   call UseBlock x, NumericLetter
                   exit sub
               end if
               Possibility=Possibility+1
           end if
           if block(x,2)=NumericLetter then
               if alphabet(block(x,1),1)=0 then
                   call UseBlock x, NumericLetter
                   exit sub
               end if
               Possibility=Possibility+1
           end if
       end if
   next x

end sub

sub UseBlock BlockNumber, NumericLetter

   block(BlockNumber, 0)=1 'Mark block as used
   BlocksUsed=BlocksUsed+1
   LetterOK=1

end sub </lang>

Output:
Rosetta Code - ABC problem (procedural solution)

>>> can_make_word("A")
True
>>> can_make_word("BARK")
True
>>> can_make_word("BOOK")
False
>>> can_make_word("TREAT")
True
>>> can_make_word("COMMON")
False
>>> can_make_word("SQUAD")
True
>>> can_make_word("CONFUSE")
True
Program complete.

<lang logo>make "blocks [[B O] [X K] [D Q] [C P] [N A] [G T] [R E] [T G] [Q D] [F S]

             [J W] [H U] [V I] [A N] [O B] [E R] [F S] [L Y] [P C] [Z M]]

to can_make? :word [:avail :blocks]

 if empty? :word [output "true]
 local "letter make "letter first :word
 foreach :avail [
   local "i     make "i     #
   local "block make "block ?
   if member? :letter :block [
     if (can_make? bf :word filter [notequal? # :i] :avail) [output "true]
   ]
 ]
 output "false

end

foreach [A BARK BOOK TREAT COMMON SQUAD CONFUSE] [

 print sentence word ? ": can_make? ?

]

bye</lang>

Output:
A: true
BARK: true
BOOK: false
TREAT: true
COMMON: false
SQUAD: true
CONFUSE: true

Lua

<lang lua>blocks = { {"B","O"}; {"X","K"}; {"D","Q"}; {"C","P"}; {"N","A"}; {"G","T"}; {"R","E"}; {"T","G"}; {"Q","D"}; {"F","S"}; {"J","W"}; {"H","U"}; {"V","I"}; {"A","N"}; {"O","B"}; {"E","R"}; {"F","S"}; {"L","Y"}; {"P","C"}; {"Z","M"}; };

function canUse(table, letter) for i,v in pairs(blocks) do if (v[1] == letter:upper() or v[2] == letter:upper()) and table[i] then table[i] = false; return true; end end return false; end

function canMake(Word) local Taken = {}; for i,v in pairs(blocks) do table.insert(Taken,true); end local found = true; for i = 1,#Word do if not canUse(Taken,Word:sub(i,i)) then found = false; end end print(found) end</lang>

Output:
canMake("A"): true
canMake("BARK"): true
canMake("BOOK"): false
canMake("TREAT"): true
canMake("COMMON"): false
canMake("SQUAD"): true
canMake("CONFUSE"): true

Maple

<lang maple>canSpell := proc(w) local blocks, i, j, word, letterFound; blocks := [["B", "O"], ["X", "K"], ["D", "Q"], ["C", "P"], ["N", "A"], ["G", "T"], ["R", "E"], ["T", "G"], ["Q", "D"], ["F", "S"], ["J", "W"], ["H", "U"], ["V", "I"], ["A", "N"], ["O", "B"], ["E", "R"], ["F", "S"], ["L", "Y"], ["P", "C"], ["Z", "M"]]; word := StringTools[UpperCase](convert(w, string)); for i to length(word) do letterFound := false; for j to numelems(blocks) do if not letterFound and (substring(word, i) = blocks[j][1] or substring(word, i) = blocks[j][2]) then blocks[j][1] := undefined; blocks[j][2] := undefined; letterFound := true; end if; end do; if not letterFound then return false; end if; end do; return true; end proc:

seq(printf("%a: %a\n", i, canSpell(i)), i in [a, Bark, bOok, treat, COMMON, squad, confuse]);</lang>

Output:
a: true
Bark: true
bOok: false
treat: true
COMMON: false
squad: true
confuse: true

Mathematica / Wolfram Language

<lang Mathematica> blocks=Partition[Characters[ToLowerCase["BOXKDQCPNAGTRETGQDFSJWHUVIANOBERFSLYPCZM"]],2]; ClearAll[DoStep,ABCBlockQ] DoStep[chars_List,blcks_List,chosen_List]:=Module[{opts},

If[chars=!={},
 opts=Select[blcks,MemberQ[#,First[chars]]&];
 {Rest[chars],DeleteCases[blcks,#,1,1],Append[chosen,#]}&/@opts
,
 Template:Chars,blcks,chosen
]

] DoStep[opts_List]:=Flatten[DoStep@@@opts,1] ABCBlockQ[str_String]:=(FixedPoint[DoStep,{{Characters[ToLowerCase[str]],blocks,{}}}]=!={}) </lang>

Output:
ABCBlockQ["A"]
ABCBlockQ["BARK"]
ABCBlockQ["BOOK"]
ABCBlockQ["TREAT"]
ABCBlockQ["COMMON"]
ABCBlockQ["SQUAD"]
ABCBlockQ["CONFUSE"]
True
True
False
True
False
True
True

MATLAB

<lang MATLAB>function testABC

   combos = ['BO' ; 'XK' ; 'DQ' ; 'CP' ; 'NA' ; 'GT' ; 'RE' ; 'TG' ; 'QD' ; ...
       'FS' ; 'JW' ; 'HU' ; 'VI' ; 'AN' ; 'OB' ; 'ER' ; 'FS' ; 'LY' ; ...
       'PC' ; 'ZM'];
   words = {'A' 'BARK' 'BOOK' 'TREAT' 'COMMON' 'SQUAD' 'CONFUSE'};
   for k = 1:length(words)
       possible = canMakeWord(words{k}, combos);
       fprintf('Can%s make word %s.\n', char(~possible.*'NOT'), words{k})
   end

end

function isPossible = canMakeWord(word, combos)

   word = lower(word);
   combos = lower(combos);
   isPossible = true;
   k = 1;
   while isPossible && k <= length(word)
       [r, c] = find(combos == word(k), 1);
       if ~isempty(r)
           combos(r, :) = ;
       else
           isPossible = false;
       end
       k = k+1;
   end

end</lang>

Output:
Can make word A.
Can make word BARK.
CanNOT make word BOOK.
Can make word TREAT.
CanNOT make word COMMON.
Can make word SQUAD.
Can make word CONFUSE.

MAXScript

Recursive

Recursively checks if the word is possible if a block is removed from the array.

<lang MAXScript> -- This is the blocks array global GlobalBlocks = #("BO","XK","DQ","CP","NA", \ "GT","RE","TG","QD","FS", \ "JW","HU","VI","AN","OB", \ "ER","FS","LY","PC","ZM")

-- This function returns true if "_str" is part of "_word", false otherwise fn occurs _str _word = ( if _str != undefined and _word != undefined then ( matchpattern _word pattern:("*"+_str+"*") ) else return false )

-- This is the main function fn isWordPossible word blocks: = -- blocks is a keyword argument ( word = toupper word -- convert the string to upper case, to make it case insensitive if blocks == unsupplied do blocks = GlobalBlocks -- if blocks (keyword argument) is unsupplied, use the global blocks array (this is for recursion)

blocks = deepcopy blocks

local pos = 1 -- start at the beginning of the word local solvedLetters = #() -- this array stores the indices of solved letters

while pos <= word.count do -- loop through every character in the word ( local possibleBlocks = #() -- this array stores the blocks which can be used to make that letter for b = 1 to Blocks.count do -- this loop finds all the possible blocks that can be used to make that letter ( if occurs word[pos] blocks[b] do ( appendifunique possibleBlocks b ) ) if possibleBlocks.count > 0 then -- if it found any blocks ( if possibleBlocks.count == 1 then -- if it found one block, then continue ( appendifunique solvedLetters pos deleteitem blocks possibleblocks[1] pos += 1 ) else -- if it found more than one ( for b = 1 to possibleBlocks.count do -- loop through every possible block ( local possibleBlock = blocks[possibleBlocks[b]] local blockFirstLetter = possibleBlock[1] local blockSecondLetter = possibleBlock[2] local matchingLetter = if blockFirstLetter == word[pos] then 1 else 2 -- ^ this is the index of the matching letter on the block

local notMatchingIndex = if matchingLetter == 1 then 2 else 1 local notMatchingLetter = possibleBlock[notMatchingIndex] -- ^ this is the other letter on the block

if occurs notMatchingLetter (substring word (pos+1) -1) then ( -- if the other letter occurs in the rest of the word local removedBlocks = deepcopy blocks -- copy the current blocks array deleteitem removedBlocks possibleBlocks[b] -- remove the item from the copied array

-- recursively check if the word is possible if that block is taken away from the array: if (isWordPossible (substring word (pos+1) -1) blocks:removedBlocks) then ( -- if it is, then remove the block and move to next character appendifunique solvedLetters pos deleteitem blocks possibleblocks[1] pos += 1 exit ) else ( -- if it isn't and it looped through every possible block, then the word is not possible if b == possibleBlocks.count do return false ) ) else ( -- if the other letter on this block doesn't occur in the rest of the word, then the letter is solved, continue appendifunique solvedLetters pos deleteitem blocks possibleblocks[b] pos += 1 exit ) ) ) ) else return false -- if it didn't find any blocks, then return false )

makeuniquearray solvedLetters -- make sure there are no duplicates in the solved array if solvedLetters.count != word.count then return false -- if number of solved letters is not equal to word length else ( -- this checks if all the solved letters are the same as the word check = "" for bit in solvedLetters do append check word[bit] if check == word then return true else return false ) ) </lang>

Output: <lang MAXScript> iswordpossible "a" true iswordpossible "bark" true iswordpossible "book" false iswordpossible "treat" true iswordpossible "common" false iswordpossible "squad" true iswordpossible "confuse" true </lang>


Non-recursive

<lang MAXScript> fn isWordPossible2 word = ( Blocks = #("BO","XK","DQ","CP","NA", \ "GT","RE","TG","QD","FS", \ "JW","HU","VI","AN","OB", \ "ER","FS","LY","PC","ZM")

       word = toupper word

local pos = 1 local solvedLetters = #() while pos <= word.count do ( for i = 1 to blocks.count do ( if (matchpattern blocks[i] pattern:("*"+word[pos]+"*")) then ( deleteitem blocks i appendifunique solvedLetters pos pos +=1 exit ) else if i == blocks.count do return false ) ) if solvedLetters.count == word.count then ( local check = "" for bit in solvedLetters do append check word[bit] if check == word then return true else return false ) else return false ) </lang>

Both versions are good for this example, but the non-recursive version won't work if the blocks are more random, because it just takes the first found block, and the recursive version decides which one to use. For example, if blocks are: #("RT","WA","WO","TB","RE") Then:

<lang MAXScript> iswordpossible "water" true iswordpossible2 "water" false </lang>

Non-recursive version quickly decides that it's not possible, even though it clearly is.

Nim

<lang nim>from strutils import contains, format, toUpper from sequtils import delete

proc canMakeWord(s: string): bool =

 var
   abcs = @["BO", "XK", "DQ", "CP", "NA", "GT", "RE", "TG", "QD", "FS",
            "JW", "HU", "VI", "AN", "OB", "ER", "FS", "LY", "PC", "ZM"]
   matched = newSeq[string]()
 if s.len > abcs.len:
   return false
 for i in 0 .. s.len - 1:
   var
     letter = s[i].toUpper
     n = 0
   for abc in abcs:
     if contains(abc, letter):
       delete(abcs, n, n)
       matched = matched & abc
       break
     else:
       inc(n)
 if matched.len == s.len:
   return true
 else:
   return false

var words = @["A", "bArK", "BOOK", "treat", "common", "sQuAd", "CONFUSE"] for word in words:

 echo format("Can the blocks make the word \"$1\"? $2", word,
   (if canMakeWord(word): "yes" else: "no"))</lang>
Output:
Can the blocks make the word "A"? yes
Can the blocks make the word "bArK"? yes
Can the blocks make the word "BOOK"? no
Can the blocks make the word "treat"? yes
Can the blocks make the word "common"? no
Can the blocks make the word "sQuAd"? yes
Can the blocks make the word "CONFUSE"? yes

Oberon-2

Works with oo2c Version 2 <lang oberon2> MODULE ABCBlocks; IMPORT

 Object,
 Out;

VAR

 blocks: ARRAY 20 OF STRING;
 
   PROCEDURE CanMakeWord(w: STRING): BOOLEAN;
   VAR
     used: ARRAY 20 OF LONGINT;
     wChars: Object.CharsLatin1;
     i,j: LONGINT;
     PROCEDURE IsUsed(i: LONGINT): BOOLEAN;
     VAR
       b: LONGINT;
     BEGIN
       b := 0;
       WHILE (b < LEN(used) - 1) & (used[b] # -1) DO
         IF used[b] = i THEN RETURN TRUE END;
         INC(b)
       END;
       RETURN FALSE
     END IsUsed;
     PROCEDURE GetBlockFor(blocks: ARRAY OF STRING; c: CHAR): LONGINT;
     VAR
       i: LONGINT;
     BEGIN
       i := 0;
       WHILE (i < LEN(blocks)) DO
         IF (blocks[i].IndexOf(c,0) >= 0) & (~IsUsed(i)) THEN RETURN i END;
         INC(i)
       END;
       
       RETURN -1;
     END GetBlockFor;
   BEGIN
     FOR i := 0 TO LEN(used) - 1 DO used[i] := -1 END;
     wChars := w(Object.String8).CharsLatin1();
     i := 0;
     WHILE (i < LEN(wChars^) - 1) DO
       j := GetBlockFor(blocks,CAP(wChars[i]));
       IF j < 0 THEN RETURN FALSE END;
       used[i] := j;
       INC(i)
     END;
     RETURN TRUE
   END CanMakeWord;
 

BEGIN

 blocks[0] := "BO";
 blocks[1] := "XK";
 blocks[2] := "DQ";
 blocks[3] := "CP";
 blocks[4] := "NA";
 blocks[5] := "GT";
 blocks[6] := "RE";
 blocks[7] := "TG";
 blocks[8] := "QD";
 blocks[9] := "FS";
 blocks[10] := "JW";
 blocks[11] := "HU";
 blocks[12] := "VI";
 blocks[13] := "AN";
 blocks[14] := "OB";
 blocks[15] := "ER";
 blocks[16] := "FS";
 blocks[17] := "LY";
 blocks[18] := "PC";
 blocks[19] := "ZM";
 Out.String("A: ");Out.Bool(CanMakeWord("A"));Out.Ln;
 Out.String("BARK: ");Out.Bool(CanMakeWord("BARK"));Out.Ln;
 Out.String("BOOK: ");Out.Bool(CanMakeWord("BOOK"));Out.Ln;
 Out.String("TREAT: ");Out.Bool(CanMakeWord("TREAT"));Out.Ln;
 Out.String("COMMON: ");Out.Bool(CanMakeWord("COMMON"));Out.Ln;
 Out.String("SQAD: ");Out.Bool(CanMakeWord("SQUAD"));Out.Ln;
 Out.String("confuse: ");Out.Bool(CanMakeWord("confuse"));Out.Ln;

END ABCBlocks. </lang> Output:

A: TRUE
BARK: TRUE
BOOK: FALSE
TREAT: TRUE
COMMON: FALSE
SQAD: TRUE
confuse: TRUE

Objeck

Translation of: Java

<lang objeck>class Abc {

 function : Main(args : String[]) ~ Nil {
   blocks := ["BO", "XK", "DQ", "CP", "NA", 
     "GT", "RE", "TG", "QD", "FS", 
     "JW", "HU", "VI", "AN", "OB", 
     "ER", "FS", "LY", "PC", "ZM"];
       
   IO.Console->Print("\"\": ")->PrintLine(CanMakeWord("", blocks));
   IO.Console->Print("A: ")->PrintLine(CanMakeWord("A", blocks));
   IO.Console->Print("BARK: ")->PrintLine(CanMakeWord("BARK", blocks));
   IO.Console->Print("book: ")->PrintLine(CanMakeWord("book", blocks));
   IO.Console->Print("treat: ")->PrintLine(CanMakeWord("treat", blocks));
   IO.Console->Print("COMMON: ")->PrintLine(CanMakeWord("COMMON", blocks));
   IO.Console->Print("SQuAd: ")->PrintLine(CanMakeWord("SQuAd", blocks));
   IO.Console->Print("CONFUSE: ")->PrintLine(CanMakeWord("CONFUSE", blocks));
 }
 
 function : CanMakeWord(word : String, blocks : String[]) ~ Bool {
   if(word->Size() = 0) {
         return true;
   };

     c := word->Get(0)->ToUpper();
     for(i := 0; i < blocks->Size(); i++;) {
     b := blocks[i];
     if(<>(b->Get(0)->ToUpper() <> c & b->Get(1)->ToUpper() <> c)) {
       Swap(0, i, blocks);
       new_word := word->SubString(1, word->Size() - 1);
       new_blocks := String->New[blocks->Size() - 1];
       Runtime->Copy(new_blocks, 0, blocks, 1, blocks->Size() - 1);
       if(CanMakeWord(new_word, new_blocks)) {
         return true;
       };
       Swap(0, i, blocks);
     };
   };
   
   return false;
 }
 
 function : native : Swap(i : Int, j : Int, arr : String[]) ~ Nil {
   tmp := arr[i];
   arr[i] := arr[j];
   arr[j] := tmp;
 }

}</lang>

"": true
A: true
BARK: true
book: false
treat: true
COMMON: false
SQuAd: true
CONFUSE: true

OCaml

<lang ocaml>let blocks = [

 ('B', 'O');  ('X', 'K');  ('D', 'Q');  ('C', 'P');
 ('N', 'A');  ('G', 'T');  ('R', 'E');  ('T', 'G');
 ('Q', 'D');  ('F', 'S');  ('J', 'W');  ('H', 'U');
 ('V', 'I');  ('A', 'N');  ('O', 'B');  ('E', 'R');
 ('F', 'S');  ('L', 'Y');  ('P', 'C');  ('Z', 'M');

]

let find_letter blocks c =

 let found, remaining =
   List.partition (fun (c1, c2) -> c1 = c || c2 = c) blocks
 in
 match found with
 | _ :: res -> Some (res @ remaining)
 | _ -> None

let can_make_word w =

 let n = String.length w in
 let rec aux i _blocks =
   if i >= n then true else
     match find_letter _blocks w.[i] with
     | None -> false
     | Some rem_blocks ->
         aux (succ i) rem_blocks
 in
 aux 0 blocks

let test label f (word, should) =

 Printf.printf "- %s %S = %B  (should: %B)\n" label word (f word) should

let () =

 List.iter (test "can make word" can_make_word) [
   "A", true;
   "BARK", true;
   "BOOK", false;
   "TREAT", true;
   "COMMON", false;
   "SQUAD", true;
   "CONFUSE", true;
 ]</lang>
Output:
 $ ocaml canmakeword.ml
 - can make word "A" = true  (should: true)
 - can make word "BARK" = true  (should: true)
 - can make word "BOOK" = false  (should: false)
 - can make word "TREAT" = true  (should: true)
 - can make word "COMMON" = false  (should: false)
 - can make word "SQUAD" = true  (should: true)
 - can make word "CONFUSE" = true  (should: true)

Oforth

<lang Oforth>["BO","XK","DQ","CP","NA","GT","RE","TG","QD","FS","JW","HU","VI","AN","OB","ER","FS","LY","PC","ZM"] const: ABCBlocks

canMakeWord(w, blocks)

| i |

  w isEmpty ifTrue: [ true return ]
  blocks size loop: i [ 
     blocks at(i) include(w first toUpper) ifFalse: [ continue ]
     canMakeWord(w right(w size 1 -), blocks del(i, i)) ifTrue: [ true return ]
     ]
  false ;</lang>
Output:
["A", "BARK", "BOOK", "TREAT", "COMMON", "SQUAD", "CONFUSE"] map(#[ ABCBlocks canMakeWord]) println
[1, 1, 0, 1, 0, 1, 1]

OpenEdge/Progress

<lang Progress (Openedge ABL)>FUNCTION canMakeWord RETURNS LOGICAL (INPUT pWord AS CHARACTER) FORWARD.

/* List of blocks */ DEFINE TEMP-TABLE ttBlocks NO-UNDO

   FIELD ttFaces AS CHARACTER FORMAT "x(1)" EXTENT 2
   FIELD ttUsed AS LOGICAL.

/* Fill in list of blocks */ RUN AddBlock("BO"). RUN AddBlock("XK"). RUN AddBlock("DQ"). RUN AddBlock("CP"). RUN AddBlock("NA"). RUN AddBlock("GT"). RUN AddBlock("Re"). RUN AddBlock("TG"). RUN AddBlock("QD"). RUN AddBlock("FS"). RUN AddBlock("JW"). RUN AddBlock("HU"). RUN AddBlock("VI"). RUN AddBlock("AN"). RUN AddBlock("OB"). RUN AddBlock("ER"). RUN AddBlock("FS"). RUN AddBlock("LY"). RUN AddBlock("PC"). RUN AddBlock("ZM").

DEFINE VARIABLE chWords AS CHARACTER EXTENT 7 NO-UNDO. ASSIGN chWords[1] = "A"

       chWords[2] = "BARK"
       chWords[3] = "BOOK"
       chWords[4] = "TREAT"
       chWords[5] = "COMMON"
       chWords[6] = "SQUAD"
       chWords[7] = "CONFUSE".

DEFINE FRAME frmResult

   WITH NO-LABELS 7 DOWN USE-TEXT.

DEFINE VARIABLE i AS INTEGER NO-UNDO. DO i = 1 TO 7:

   DISPLAY chWords[i] + " = " + STRING(canMakeWord(chWords[i])) FORMAT "x(25)" WITH FRAME frmResult.  
   DOWN WITH FRAME frmResult.

END.


PROCEDURE AddBlock:

   DEFINE INPUT PARAMETER i-chBlockvalue AS CHARACTER NO-UNDO.
   IF (LENGTH(i-chBlockValue) <> 2)
       THEN RETURN ERROR.
   CREATE ttBlocks.
   ASSIGN  ttBlocks.ttFaces[1] = SUBSTRING(i-chBlockValue, 1, 1)
           ttBlocks.ttFaces[2] = SUBSTRING(i-chBlockValue, 2, 1).

END PROCEDURE.


FUNCTION blockInList RETURNS LOGICAL (pChar AS CHARACTER):

   /* Find first unused block in list */
   FIND FIRST ttBlocks WHERE (ttBlocks.ttFaces[1] = pChar
                              OR ttBlocks.ttFaces[2] = pChar)
                         AND NOT ttBlocks.ttUsed NO-ERROR.
   IF (AVAILABLE ttBlocks) THEN DO:
       /* found it! set to used and return true */
       ASSIGN ttBlocks.ttUsed = TRUE.
       RETURN TRUE.
   END.
   ELSE RETURN FALSE.

END FUNCTION.


FUNCTION canMakeWord RETURNS LOGICAL (INPUT pWord AS CHARACTER):

   DEFINE VARIABLE i AS INTEGER NO-UNDO.
   DEFINE VARIABLE chChar AS CHARACTER NO-UNDO.
   /* Word has to be valid */
   IF (LENGTH(pWord) = 0) 
       THEN RETURN FALSE.
   DO i = 1 TO LENGTH(pWord):
       /* get the char */
       chChar = SUBSTRING(pWord, i, 1).
       /* Check to see if this is a letter? */
       IF ((ASC(chChar) < 65) OR (ASC(chChar) > 90) AND
           (ASC(chChar) < 97) OR (ASC(chChar) > 122)) 
           THEN RETURN FALSE.
       /* Is block is list (and unused) */
       IF NOT blockInList(chChar)
           THEN RETURN FALSE.
   END.
   /* Reset all blocks */
   FOR EACH ttBlocks:
       ASSIGN ttUsed = FALSE.
   END.
   RETURN TRUE.

END FUNCTION. </lang>

Output:
A = yes
BARK = yes
BOOK = no
TREAT = yes
COMMON = no
SQUAD = yes
CONFUSE = yes

PARI/GP

<lang parigp>BLOCKS = "BOXKDQCPNAGTRETGQDFSJWHUVIANOBERFSLYPCZM"; WORDS = ["A","Bark","BOOK","Treat","COMMON","SQUAD","conFUSE"];

can_make_word(w) = check(Vecsmall(BLOCKS), Vecsmall(w))

check(B,W,l=1,n=1) = {

 if (l > #W, return(1), n > #B, return(0));
 
 forstep (i = 1, #B-2, 2,
   if (B[i] != bitand(W[l],223) && B[i+1] != bitand(W[l],223), next());
   B[i] = B[i+1] = 0;
   if (check(B, W, l+1, n+2), return(1))
 );
 0

}

for (i = 1, #WORDS, printf("%s\t%d\n", WORDS[i], can_make_word(WORDS[i])));</lang>

Output:

A	1
Bark	1
BOOK	0
Treat	1
COMMON	0
SQUAD	1
conFUSE	1


Pascal

Works with: Free Pascal version 2.6.2

<lang Pascal>

  1. !/usr/bin/instantfpc

//program ABCProblem;

{$mode objfpc}{$H+}

uses SysUtils, Classes;

const

 // every couple of chars is a block
 // remove one by replacing its 2 chars by 2 spaces
 Blocks =  'BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM';
 BlockSize = 3;

function can_make_word(Str: String): boolean; var

 wkBlocks: string = Blocks;
 c: Char;
 iPos : Integer;

begin

 // all chars to uppercase
 Str := UpperCase(Str);
 Result := Str <> ;
 if Result then
 begin
   for c in Str do
   begin
     iPos := Pos(c, wkBlocks);
     if (iPos > 0) then
     begin
       // Char found
       wkBlocks[iPos] := ' ';
       // Remove the other face
       if (iPos mod BlockSize = 1) then
         wkBlocks[iPos + 1] := ' '
       else
         wkBlocks[iPos - 1] := ' ';          
     end
     else
     begin
       //  missed
       Result := False;
       break;
     end;
   end;
 end;
 // Debug...
 //WriteLn(Blocks);
 //WriteLn(wkBlocks);

End;

procedure TestABCProblem(Str: String); const

 boolStr : array[boolean] of String = ('False', 'True');

begin

 WriteLn(Format('>>> can_make_word("%s")%s%s', [Str, LineEnding, boolStr[can_make_word(Str)]]));

End;

begin

 TestABCProblem('A');
 TestABCProblem('BARK');
 TestABCProblem('BOOK');
 TestABCProblem('TREAT');
 TestABCProblem('COMMON');
 TestABCProblem('SQUAD');
 TestABCProblem('CONFUSE');

END.</lang>

Output:
./ABCProblem.pas 
>>> can_make_word("A")
True
>>> can_make_word("BARK")
True
>>> can_make_word("BOOK")
False
>>> can_make_word("TREAT")
True
>>> can_make_word("COMMON")
False
>>> can_make_word("SQUAD")
True
>>> can_make_word("CONFUSE")
True

Perl

Recursive solution that can handle characters appearing on different blocks: <lang perl>#!/usr/bin/perl use warnings; use strict;


sub can_make_word {

   my ($word, @blocks) = @_;
   $_ = uc join q(), sort split // for @blocks;
   my %blocks;
   $blocks{$_}++ for @blocks;
   return _can_make_word(uc $word, %blocks)

}


sub _can_make_word {

   my ($word, %blocks) = @_;
   my $char = substr $word, 0, 1, q();
   my @candidates = grep 0 <= index($_, $char), keys %blocks;
   for my $candidate (@candidates) {
       next if $blocks{$candidate} <= 0;
       local $blocks{$candidate} = $blocks{$candidate} - 1;
       return 1 if q() eq $word or _can_make_word($word, %blocks);
   }
   return

}</lang>

Testing: <lang perl>use Test::More tests => 8; my @blocks1 = qw(BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM); is(can_make_word("A", @blocks1), 1); is(can_make_word("BARK", @blocks1), 1); is(can_make_word("BOOK", @blocks1), undef); is(can_make_word("TREAT", @blocks1), 1); is(can_make_word("COMMON", @blocks1), undef); is(can_make_word("SQUAD", @blocks1), 1); is(can_make_word("CONFUSE", @blocks1), 1); my @blocks2 = qw(US TZ AO QA); is(can_make_word('auto', @blocks2), 1); </lang>

Perl 6

Works with: rakudo version 6.0.c

Blocks are stored as precompiled regexes. We do an initial pass on the blockset to include in the list only those regexes that match somewhere in the current word. Conveniently, regexes scan the word for us. <lang perl6>multi can-spell-word(Str $word, @blocks) {

   my @regex = @blocks.map({ my @c = .comb; rx/<@c>/ }).grep: { .ACCEPTS($word.uc) }
   can-spell-word $word.uc.comb.list, @regex;

}

multi can-spell-word([$head,*@tail], @regex) {

   for @regex -> $re {
       if $head ~~ $re {
           return True unless @tail;
           return False if @regex == 1;
           return True if can-spell-word @tail, list @regex.grep: * !=== $re;
       }
   }
   False;

}

my @b = <BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM>;

for <A BaRK BOoK tREaT COmMOn SqUAD CoNfuSE> {

   say "$_     &can-spell-word($_, @b)";

}</lang>

Output:
A	True
BaRK	True
BOoK	False
tREaT	True
COmMOn	False
SqUAD	True
CoNfuSE	True

Phix

<lang Phix> -- Here is my recursive solution which also solves the extra problems on the discussion page:

sequence blocks = {"BO","XK","DQ","CP","NA","GT","RE","TG","QD","FS",

                  "JW","HU","VI","AN","OB","ER","FS","LY","PC","ZM"}

sequence words = {"","A","BarK","BOOK","TrEaT","COMMON","SQUAD","CONFUSE"}

--sequence blocks = {"US","TZ","AO","QA"} --sequence words = {"AuTO"}

--sequence blocks = {"AB","AB","AC","AC"} --sequence words = {"abba"}

sequence used = repeat(0,length(blocks))

function ABC_Solve(sequence word, integer idx) integer ch integer res = 0

   if idx>length(word) then
       res = 1
   else
       ch = word[idx]
       for k=1 to length(blocks) do
           if used[k]=0
           and find(ch,blocks[k]) then
               used[k] = 1
               res = ABC_Solve(word,idx+1)
               used[k] = 0
               if res then exit end if
           end if
       end for
   end if
   return res

end function

constant TF = {"False","True"} procedure ABC_Problem()

   for i=1 to length(words) do
       printf(1,"%s: %s\n",{words[i],TF[ABC_Solve(upper(words[i]),1)+1]})
   end for
   if getc(0) then end if

end procedure

   ABC_Problem()

</lang>

Output:
: True
A: True
BarK: True
BOOK: False
TrEaT: True
COMMON: False
SQUAD: True
CONFUSE: True

PHP

<lang PHP> <?php $words = array("A", "BARK", "BOOK", "TREAT", "COMMON", "SQUAD", "Confuse");

function canMakeWord($word) {

   $word = strtoupper($word);
   $blocks = array(
           "BO", "XK", "DQ", "CP", "NA",
           "GT", "RE", "TG", "QD", "FS",
           "JW", "HU", "VI", "AN", "OB",
           "ER", "FS", "LY", "PC", "ZM",
   );
   foreach (str_split($word) as $char) {
       foreach ($blocks as $k => $block) {
           if (strpos($block, $char) !== FALSE) {
               unset($blocks[$k]);
               continue(2);
           }
       }
       return false;
   }
   return true;

}

foreach ($words as $word) {

   echo $word.': ';
   echo canMakeWord($word) ? "True" : "False";
   echo "\r\n";

}</lang>

Output:
A: True
BARK: True
BOOK: False
TREAT: True
COMMON: False
SQUAD: True
Confuse: True

PicoLisp

Mapping and recursion. <lang>(setq *Blocks

  '((B O) (X K) (D Q) (C P) (N A) (G T) (R E) 
  (T G) (Q D) (F S) (J W) (H U) (V I) (A N)
  (O B) (E R) (F S) (L Y) (P C) (Z M) ) )

(setq *Words '("" "1" "A" "BARK" "BOOK" "TREAT"

              "Bbb" "COMMON" "SQUAD" "Confuse"
              "abba" "ANBOCPDQERSFTGUVWXLZ") )

(de abc (W B)

  (let Myblocks (copy B)
     (fully
        '((C)
           (when (seek '((Lst) (member C (car Lst))) Myblocks)
              (set @)
              T ) )
     (chop (uppc W)) ) ) )

(de abcR (W B)

  (nond
     ((car W) T)
     ((car B) NIL)
     (NIL
        (setq W (chop W))
        (let? I
           (find
              '((Lst) (member (uppc (car W)) Lst))
              B )
           (abcR (cdr W) (delete I B)) ) ) ) )               

(for Word *Words

  (println Word (abc Word *Blocks) (abcR Word *Blocks)) )
   

(bye)</lang>

PL/I

version 1

<lang pli>ABC: procedure options (main); /* 12 January 2014 */

  declare word character (20) varying, blocks character (200) varying initial
     ('((B O) (X K) (D Q) (C P) (N A) (G T) (R E) (T G) (Q D) (F S)
       (J W) (H U) (V I) (A N) (O B) (E R) (F S) (L Y) (P C) (Z M))');
  declare tblocks character (200) varying;
  declare (true value ('1'b), false value ('0'b), flag) bit (1);
  declare ch character (1);
  declare (i, k) fixed binary;
  do word = 'A', 'BARK', 'BOOK', 'TREAT', 'COMMON', 'SQuAd', 'CONFUSE';
     flag = true;
     tblocks = blocks;
     do i = 1 to length(word)
     while(flag = true);
        ch = substr(word, i, 1);
        k = index(tblocks, uppercase(ch));
        if k = 0 then
           flag = false;
        else /* Found a block with the letter on it. */
           substr(tblocks, k-1, 4) = '   '; /* Delete the block. */
     end;
     if flag then put skip list (word, 'true'); else put skip list (word, 'false');
  end;

end ABC;</lang>

A                       true 
BARK                    true 
BOOK                    false 
TREAT                   true 
COMMON                  false 
SQuAd                   true 
CONFUSE                 true

version 2

<lang pli>*process source attributes xref or(!) options nest;

abc: Proc Options(main);
/* REXX --------------------------------------------------------------
* 10.01.2013 Walter Pachl  counts the number of possible ways
* translated from Rexx version 2
*-------------------------------------------------------------------*/
Dcl (ADDR,HBOUND,INDEX,LEFT,LENGTH,MAX,SUBSTR,TRANSLATE) builtin;
Dcl sysprint Print;
Dcl (i,j,k,m,mm,wi,wj,wlen,ways,lw) Bin Fixed(15);
Dcl blocks(20) Char(2)
       Init('BO','XK','DQ','CP','NA','GT','RE','TG','QD','FS','JW',
            'HU','VI','AN','OB','ER','FS','LY','PC','ZM');
Dcl blk Char(2);
Dcl words(8) Char(7) Var
       Init('$','A','baRk','bOOk','trEat','coMMon','squaD','conFuse');
Dcl word     Char(7) Var;
Dcl c Char(1);
Dcl (show,cannot) Bit(1) Init('0'b);
Dcl poss(100,0:100) Pic'99';  poss=0;
Dcl s(20,100) char(100) Var;
Dcl str Char(100);
Dcl 1 *(30) Based(addr(str)),
     2 strp Pic'99',
     2 * Char(1);
Dcl ns(20) Bin Fixed(15) Init((20)0);
Dcl ol(100) Char(100) Var;
Dcl os      Char(100) Var;
wlen=0;
Dcl lower Char(26) Init('abcdefghijklmnopqrstuvwxyz');
Dcl upper Char(26) Init('ABCDEFGHIJKLMNOPQRSTUVWXYZ');
Do wi=1 To hbound(words);
  wlen=max(wlen,length(words(wi)));
  End;
Do wi=1 To hbound(words);
  word = translate(words(wi),upper,lower);
  ways=0;
  lw=length(word);
  cannot='0'b;
  poss=0;
  ns=0;
  ol=;
iloop:
  Do i=1 To lw;                       /* loop over the characters   */
    c=substr(word,i,1);               /* the current character      */
    Do j=1 To hbound(blocks);         /* loop over blocks           */
      blk=blocks(j);
      If index(blk,c)>0 Then Do;  /* block can be used in this pos( */
        poss(i,0)+=1;        /* number of possible blocks for pos i */
        poss(i,poss(i,0))=j;
        End;
      End;
    If poss(i,0)=0 Then Do;
      Leave iloop;
      End;
    End;
  If i>lw Then Do;                     /* no prohibitive character  */
    ns=0;
    Do j=1 To poss(1,0);       /* build possible strings for char 1 */
      ns(1)+=1;;
      s(1,j)=poss(1,j);
      End;
    Do m=2 To lw;        /* build possible strings for chars 1 to i */
      mm=m-1;
      Do j=1 To ns(mm);
        Do k=1 To poss(m,0);
          ns(m)+=1;
          s(m,ns(m))=s(mm,j)!!' '!!poss(m,k);
          End;
        End;
      End;
    Do m=1 To ns(lw);
      If valid(s(lw,m)) Then Do;
        ways+=1;
        str=s(lw,m);
        Do k=1 To lw;
          ol(ways)=ol(ways)!!blocks(strp(k))!!' ';
          End;
        End;
      End;
    End;
/*--------------------------------------------------------------------
* now show the result
*-------------------------------------------------------------------*/
  os=left('!!word!!',wlen+2);
  Select;
    When(ways=0)
      os=os!!' cannot be spelt.';
    When(ways=1)
      os=os!!' can be spelt.';
    Otherwise
      os=os!!' can be spelt in'!!ways!!' ways.';
    End;
  Put Skip List(os);
  If show Then Do;
    Do wj=1 To ways;
      Put Edit('          '!!ol(wj))(Skip,a);
      End;
    End;
  End;
Return;
valid: Procedure(list) Returns(bit(1));
/*--------------------------------------------------------------------
* Check if the same block is used more than once -> 0
* Else: the combination is valid
*-------------------------------------------------------------------*/
Dcl list Char(*) Var;
Dcl i Bin Fixed(15);
Dcl used(20) Bit(1);
str=list;
used='0'b;
Do i=1 To lw;
  If used(strp(i)) Then
    Return('0'b);
  used(strp(i))='1'b;
  End;
Return('1'b);
End;
End;</lang>
Output:
'$'       cannot be spelt.
'A'       can be spelt in        2 ways.
'BARK'    can be spelt in        8 ways.
'BOOK'    cannot be spelt.
'TREAT'   can be spelt in        8 ways.
'COMMON'  cannot be spelt.
'SQUAD'   can be spelt in        8 ways.
'CONFUSE' can be spelt in       32 ways.

PowerBASIC

Works with PowerBASIC 6 Console Compiler

<lang PowerBASIC>#COMPILE EXE

  1. DIM ALL

' ' A B C p r o b l e m . b a s ' ' by Geary Chopoff ' for Chopoff Consulting and RosettaCode.org ' on 2014Jul23 ' '2014Jul23 ' 'You are given a collection of ABC blocks. Just like the ones you had when you were a kid. 'There are twenty blocks with two letters on each block. You are guaranteed to have a complete 'alphabet amongst all sides of the blocks. The sample blocks are: '((B O) (X K) (D Q) (C P) (N A) (G T) (R E) (T G) (Q D) (F S) (J W) (H U) (V I) (A N) (O B) (E R) (F S) (L Y) (P C) (Z M)) 'The goal of this task is to write a function that takes a string and can determine whether 'you can spell the word with the given collection of blocks. ' 'The rules are simple: '1.Once a letter on a block is used that block cannot be used again '2.The function should be case-insensitive '3. Show your output on this page for the following words: ' A, BARK, BOOK, TREAT, COMMON, SQUAD, CONFUSE '----------------------------------------------------------------------------- ' G l o b a l C o n s t a n t s ' %Verbose = 0 'make this 1 to have a lot of feedback %MAX_BLOCKS = 20 'total number of blocks %MAX_SIDES = 2 'total number of sides containing a unique letter per block

%MAX_ASC = 255 %FALSE = 0 'this is correct because there is ONLY ONE value for FALSE %TRUE = (NOT %FALSE) 'this is one of MANY values of TRUE! $FLAG_TRUE = "1" $FLAG_FALSE = "0" '----------------------------------------------------------------------------- ' G l o b a l V a r i a b l e s ' GLOBAL blk() AS STRING '----------------------------------------------------------------------------- 'i n i t B l o c k s ' ' as we will use this array only once we build it each time program is run ' SUB initBlocks

LOCAL j AS INTEGER
   j=1
   blk(j)="BO"
   j=j+1
   blk(j)="XK"
   j=j+1
   blk(j)="DQ"
   j=j+1
   blk(j)="CP"
   j=j+1
   blk(j)="NA"
   j=j+1
   blk(j)="GT"
   j=j+1
   blk(j)="RE"
   j=j+1
   blk(j)="TG"
   j=j+1
   blk(j)="QD"
   j=j+1
   blk(j)="FS"
   j=j+1
   blk(j)="JW"
   j=j+1
   blk(j)="HU"
   j=j+1
   blk(j)="VI"
   j=j+1
   blk(j)="AN"
   j=j+1
   blk(j)="OB"
   j=j+1
   blk(j)="ER"
   j=j+1
   blk(j)="FS"
   j=j+1
   blk(j)="LY"
   j=j+1
   blk(j)="PC"
   j=j+1
   blk(j)="ZM"
   IF j <> %MAX_BLOCKS THEN
       STDOUT "initBlocks:Error: j is not same as MAX_BLOCKS!",j,%MAX_BLOCKS
   END IF

END SUB '----------------------------------------------------------------------------- ' m a k e W o r d ' FUNCTION makeWord(tryWord AS STRING) AS BYTE

LOCAL retTF AS BYTE
LOCAL j AS INTEGER
LOCAL s AS INTEGER         'which side of block we are looking at
LOCAL k AS INTEGER
LOCAL c AS STRING          'character in tryWord we are looking for


   FOR j = 1 TO LEN(tryWord)
       c = UCASE$(MID$(tryWord,j,1))   'character we want to show with block
       retTF = %FALSE                  'we assume this will fail
       FOR k = 1 TO %MAX_BLOCKS
           IF LEN(blk(k)) = %MAX_SIDES THEN
               FOR s = 1 TO %MAX_SIDES
                   IF c = MID$(blk(k),s,1) THEN
                       retTF = %TRUE   'this block has letter we want
                       blk(k) = ""     'remove this block from further consideration
                       EXIT FOR
                   END IF
               NEXT s
           END IF
           IF retTF THEN EXIT FOR      'can go on to next character in word
       NEXT k
       IF ISFALSE retTF THEN EXIT FOR  'if character not found then all is done
   NEXT j
   FUNCTION = retTF

END FUNCTION '----------------------------------------------------------------------------- ' P B M A I N ' FUNCTION PBMAIN () AS LONG

DIM blk(1 TO %MAX_BLOCKS, 1 TO %MAX_SIDES) AS STRING
LOCAL cmdLine AS STRING
   initBlocks              'setup global array of blocks
   cmdLine=COMMAND$
   IF LEN(cmdLine)= 0 THEN
       STDOUT "Useage for ABCproblem Version 1.00:"
       STDOUT ""
       STDOUT "     >ABCproblem tryThisWord"
       STDOUT ""
       STDOUT "Where tryThisWord is a word you want to see if"+STR$(%MAX_BLOCKS)+" blocks can make."
       STDOUT "If word can be made TRUE is returned."
       STDOUT "Otherwise FALSE is returned."
       EXIT FUNCTION
   END IF
   IF INSTR(TRIM$(cmdLine)," ") = 0 THEN
       IF makeWord(cmdLine) THEN
           STDOUT "TRUE"
       ELSE
           STDOUT "FALSE"
       END IF
   ELSE
       STDOUT "Error:Missing word to try to make with blocks!  <" & cmdLine & ">"
       EXIT FUNCTION
   END IF

END FUNCTION </lang>

Output:
$ FALSE
A TRUE
bark TRUE
bOOk FALSE
treAT TRUE
COmmon FALSE
sQuaD TRUE
CONFUSE TRUE
GearyChopoff TRUE

PowerShell

<lang powershell><# .Synopsis

 ABC Problem

.DESCRIPTION

  You are given a collection of ABC blocks. Just like the ones you had when you were a kid. 
  There are twenty blocks with two letters on each block. You are guaranteed to have a 
  complete alphabet amongst all sides of the blocks
  blocks = "BO","XK","DQ","CP","NA","GT","RE","TG","QD","FS","JW","HU","VI","AN","OB","ER","FS","LY","PC","ZM"
  The goal of this task is to write a function that takes a string and can determine whether 
  you can spell the word with the given collection of blocks. 
  The rules are simple: 
       1.Once a letter on a block is used that block cannot be used again 
       2.The function should be case-insensitive 
       3. Show your output on this page for the following words:
       >>> can_make_word("A")
       True
       >>> can_make_word("BARK")
       True
       >>> can_make_word("BOOK")
       False
       >>> can_make_word("TREAT")
       True
       >>> can_make_word("COMMON")
       False
       >>> can_make_word("SQUAD")
       True
       >>> can_make_word("CONFUSE")
       True
  Using the examples below  you can either see just the value or 
  status and the values using the verbose switch

.EXAMPLE

  test-blocks -testword confuse

.EXAMPLE

  test-blocks -testword confuse -verbose
  1. >

function test-blocks { [CmdletBinding()] # [OutputType([int])] Param ( # word to test against blocks [Parameter(Mandatory = $true, ValueFromPipelineByPropertyName = $true)] $testword

)

$word = $testword

#define array of blocks [System.Collections.ArrayList]$blockarray = "BO", "XK", "DQ", "CP", "NA", "GT", "RE", "TG", "QD", "FS", "JW", "HU", "VI", "AN", "OB", "ER", "FS", "LY", "PC", "ZM"

#send word to chararray $chararray = $word.ToCharArray() $chars = $chararray

#get the character count $charscount = $chars.count

#get the initial count of the blocks $blockcount = $blockarray.Count

#find out how many blocks should be left from the difference #of the blocks and characters in the word - 1 letter/1 block $correctblockcount = $blockcount - $charscount

#loop through the characters in the word foreach ($char in $chars) {

#loop through the blocks foreach ($block in $blockarray) {

#check the current character against each letter on the current block #and break if found so the array can reload if ($char -in $block[0] -or $char -in $block[1]) {

write-verbose "match for letter - $char - removing block $block" $blockarray.Remove($block) break

}

}

} #get final count of blocks left in array to determine if the word was #correctly made $finalblockcount = $blockarray.count if ($finalblockcount -ne $correctblockcount) { write-verbose "$word : $false " return $false } else { write-verbose "$word : $true " return $true }

}

  1. loop all the words and pass them to the function

$wordlist = "a", "bark", "book", "treat", "common", "squad", "confuse" foreach ($word in $wordlist) { test-blocks -testword $word -Verbose }</lang>

Output:
VERBOSE: match for letter - a - removing block NA
VERBOSE: a : True 
True
VERBOSE: match for letter - b - removing block BO
VERBOSE: match for letter - a - removing block NA
VERBOSE: match for letter - r - removing block RE
VERBOSE: match for letter - k - removing block XK
VERBOSE: bark : True 
True
VERBOSE: match for letter - b - removing block BO
VERBOSE: match for letter - o - removing block OB
VERBOSE: match for letter - k - removing block XK
VERBOSE: book : False 
False
VERBOSE: match for letter - t - removing block GT
VERBOSE: match for letter - r - removing block RE
VERBOSE: match for letter - e - removing block ER
VERBOSE: match for letter - a - removing block NA
VERBOSE: match for letter - t - removing block TG
VERBOSE: treat : True 
True
VERBOSE: match for letter - c - removing block CP
VERBOSE: match for letter - o - removing block BO
VERBOSE: match for letter - m - removing block ZM
VERBOSE: match for letter - o - removing block OB
VERBOSE: match for letter - n - removing block NA
VERBOSE: common : False 
False
VERBOSE: match for letter - s - removing block FS
VERBOSE: match for letter - q - removing block DQ
VERBOSE: match for letter - u - removing block HU
VERBOSE: match for letter - a - removing block NA
VERBOSE: match for letter - d - removing block QD
VERBOSE: squad : True 
True
VERBOSE: match for letter - c - removing block CP
VERBOSE: match for letter - o - removing block BO
VERBOSE: match for letter - n - removing block NA
VERBOSE: match for letter - f - removing block FS
VERBOSE: match for letter - u - removing block HU
VERBOSE: match for letter - s - removing block FS
VERBOSE: match for letter - e - removing block RE
VERBOSE: confuse : True 
True

or without verbose

True
True
False
True
False
True
True

Prolog

Traditional

Works with SWI-Prolog 6.5.3

<lang Prolog>abc_problem :- maplist(abc_problem, [, 'A', bark, bOOk, treAT, 'COmmon', sQuaD, 'CONFUSE']).


abc_problem(Word) :- L = [[b,o],[x,k],[d,q],[c,p],[n,a],[g,t],[r,e],[t,g],[q,d],[f,s], [j,w],[h,u],[v,i],[a,n],[o,b],[e,r],[f,s],[l,y],[p,c],[z,m]],

( abc_problem(L, Word) -> format('~w OK~n', [Word]) ; format('~w KO~n', [Word])).

abc_problem(L, Word) :- atom_chars(Word, C_Words), maplist(downcase_atom, C_Words, D_Words), can_makeword(L, D_Words).

can_makeword(_L, []).

can_makeword(L, [H | T]) :- ( select([H, _], L, L1); select([_, H], L, L1)), can_makeword(L1, T). </lang>

Output:
 ?- abc_problem.
 OK
A OK
bark OK
bOOk KO
treAT OK
COmmon KO
sQuaD OK
CONFUSE OK
true.


Constraint Handling Rules

An approach using [CHR https://dtai.cs.kuleuven.be/CHR/] via SWI-Prolog's [library(chr) http://www.swi-prolog.org/pldoc/man?section=chr] and a module I'm working on for composing predicates composer:

Works with: SWI Prolog 7

<lang Prolog>:- use_module([ library(chr),

               abathslib(protelog/composer) ]).
- chr_constraint blocks, block/1, letter/1, word_built.

can_build_word(Word) :-

   maplist(block, [(b,o),(x,k),(d,q),(c,p),(n,a),(g,t),(r,e),(t,g),(q,d),(f,s),
                   (j,w),(h,u),(v,i),(a,n),(o,b),(e,r),(f,s),(l,y),(p,c),(z,m)]),
   maplist(letter) <- string_chars <- string_lower(Word),     %% using the `composer` module
   word_built,
   !.

'take letter and block' @ letter(L), block((A,B)) <=> L == A ; L == B | true. 'fail if letters remain' @ word_built, letter(_) <=> false.

%% These rules, removing remaining constraints from the store, are just cosmetic: 'clean up blocks' @ word_built \ block(_) <=> true. 'word was built' @ word_built <=> true.</lang>


Demonstration:

<lang Prolog>?- can_build_word("A"). true. ?- can_build_word("BARK"). true. ?- can_build_word("BOOK"). false. ?- can_build_word("TREAT"). true. ?- can_build_word("COMMON"). false. ?- can_build_word("SQUAD"). true. ?- can_build_word("CONFUSE"). true.</lang>

PureBasic

PureBasic: Iterative

<lang purebasic>EnableExplicit

  1. LETTERS = "BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM "

Procedure.s can_make_word(word.s)

 Define.s letters = #LETTERS, buffer
 Define.i index1, index2
 Define.b match
 For index1=1 To Len(word)
   index2=1 : match=#False
   Repeat    
     buffer=StringField(letters,index2,Space(1))
     If FindString(buffer,Mid(word,index1,1),1,#PB_String_NoCase)
       letters=RemoveString(letters,buffer+Chr(32),0,1,1)
       match=#True
       Break
     EndIf
     index2+1    
   Until index2>CountString(letters,Space(1))
   If Not match : ProcedureReturn word+#TAB$+"FALSE" : EndIf
 Next
 ProcedureReturn word+#TAB$+"TRUE"

EndProcedure

OpenConsole() PrintN(can_make_word("a")) PrintN(can_make_word("BaRK")) PrintN(can_make_word("BOoK")) PrintN(can_make_word("TREAt")) PrintN(can_make_word("cOMMON")) PrintN(can_make_word("SqUAD")) PrintN(can_make_word("COnFUSE")) Input()</lang>

PureBasic: Recursive

<lang purebasic>Define.i

  1. LETTERS = "BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM "

Macro test(t)

 Print(t+#TAB$+#TAB$+"= ") : If can_make_word(t) : PrintN("True") : Else : PrintN("False") : EndIf

EndMacro

Procedure.s residue(s$,n.i)

 ProcedureReturn Left(s$,Int(n/3)*3)+Mid(s$,Int(n/3)*3+4)

EndProcedure

Procedure.b can_make_word(word$,letters$=#LETTERS)

 n=FindString(letters$,Left(word$,1),1,#PB_String_NoCase)
 If Len(word$) And n : ProcedureReturn can_make_word(Mid(word$,2),residue(letters$,n)) : EndIf
 If Not Len(word$)   : ProcedureReturn #True : Else : ProcedureReturn #False           : EndIf

EndProcedure

OpenConsole() test("a")  : test("BaRK")  : test("BOoK")  : test("TREAt") test("cOMMON")  : test("SqUAD")  : test("COnFUSE") Input()</lang>

Output:
a               = True
BaRK            = True
BOoK            = False
TREAt           = True
cOMMON          = False
SqUAD           = True
COnFUSE         = True

Python

Python: Iterative, with tests

<lang python> Note that this code is broken, e.g., it won't work when blocks = [("A", "B"), ("A","C")] and the word is "AB", where the answer should be True, but the code returns False. blocks = [("B", "O"),

         ("X", "K"),
         ("D", "Q"),
         ("C", "P"),
         ("N", "A"),
         ("G", "T"),
         ("R", "E"),
         ("T", "G"),
         ("Q", "D"),
         ("F", "S"),
         ("J", "W"),
         ("H", "U"),
         ("V", "I"),
         ("A", "N"),
         ("O", "B"),
         ("E", "R"),
         ("F", "S"),
         ("L", "Y"),
         ("P", "C"),
         ("Z", "M")]


def can_make_word(word, block_collection=blocks):

   """
   Return True if `word` can be made from the blocks in `block_collection`.
   >>> can_make_word("")
   False
   >>> can_make_word("a")
   True
   >>> can_make_word("bark")
   True
   >>> can_make_word("book")
   False
   >>> can_make_word("treat")
   True
   >>> can_make_word("common")
   False
   >>> can_make_word("squad")
   True
   >>> can_make_word("coNFused")
   True
   """
   if not word:
       return False
   blocks_remaining = block_collection[:]
   for char in word.upper():
       for block in blocks_remaining:
           if char in block:
               blocks_remaining.remove(block)
               break
       else:
           return False
   return True


if __name__ == "__main__":

   import doctest
   doctest.testmod()
   print(", ".join("'%s': %s" % (w, can_make_word(w)) for w in
                   ["", "a", "baRk", "booK", "treat", 
                    "COMMON", "squad", "Confused"]))

</lang>

Output:
'': False, 'a': True, 'baRk': True, 'booK': False, 'treat': True, 'COMMON': False, 'squad': True, 'Confused': True

Python: Recursive

<lang python>BLOCKS = 'BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM'.split()

def _abc(word, blocks):

   for i, ch in enumerate(word):
       for blk in (b for b in blocks if ch in b):
           whatsleft = word[i + 1:]
           blksleft = blocks[:]
           blksleft.remove(blk)
           if not whatsleft: 
               return True, blksleft
           if not blksleft: 
               return False, blksleft
           ans, blksleft = _abc(whatsleft, blksleft)
           if ans:
               return ans, blksleft
       else:
           break
   return False, blocks

def abc(word, blocks=BLOCKS):

   return _abc(word.upper(), blocks)[0]

if __name__ == '__main__':

   for word in [] + 'A BARK BoOK TrEAT COmMoN SQUAD conFUsE'.split():
       print('Can we spell %9r? %r' % (word, abc(word)))</lang>
Output:
Can we spell       ''? False
Can we spell       'A'? True
Can we spell    'BARK'? True
Can we spell    'BoOK'? False
Can we spell   'TrEAT'? True
Can we spell  'COmMoN'? False
Can we spell   'SQUAD'? True
Can we spell 'conFUsE'? True

Python: Recursive, telling how

<lang python>def mkword(w, b):

   if not w: return []
   c,w = w[0],w[1:]
   for i in range(len(b)):
       if c in b[i]:
           m = mkword(w, b[0:i] + b[i+1:])
           if m != None: return [b[i]] + m

def abc(w, blk):

   return mkword(w.upper(), [a.upper() for a in blk])

blocks = 'BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM'.split()

for w in ", A, bark, book, treat, common, SQUAD, conFUsEd".split(', '):

   print '\ + w + '\ + ' ->', abc(w, blocks)</lang>
Output:

Note the case of empty list returned for empty string; whether it means true or false is up to you.

'' -> []
'A' -> ['NA']
'bark' -> ['BO', 'NA', 'RE', 'XK']
'book' -> None
'treat' -> ['GT', 'RE', 'ER', 'NA', 'TG']
'common' -> None
'SQUAD' -> ['FS', 'DQ', 'HU', 'NA', 'QD']
'conFUsEd' -> ['CP', 'BO', 'NA', 'FS', 'HU', 'FS', 'RE', 'DQ']

R

With recursion

Vectorised function for R which will take a character vector and return a logical vector of equal length with TRUE and FALSE as appropriate for words which can/cannot be made with the blocks.

<lang R>blocks <- rbind(c("B","O"),

c("X","K"), 
c("D","Q"), 
c("C","P"), 
c("N","A"), 
c("G","T"), 
c("R","E"), 
c("T","G"), 
c("Q","D"), 
c("F","S"), 
c("J","W"), 
c("H","U"), 
c("V","I"), 
c("A","N"), 
c("O","B"), 
c("E","R"), 
c("F","S"), 
c("L","Y"), 
c("P","C"), 
c("Z","M"))

canMake <- function(x) {

 x <- toupper(x)
 used <- rep(FALSE, dim(blocks)[1L])
 charList <- strsplit(x, character(0))
 tryChars <- function(chars, pos, used, inUse=NA) {
   if (pos > length(chars)) {
     TRUE
   } else {
     used[inUse] <- TRUE
     possible <- which(blocks == chars[pos] & !used, arr.ind=TRUE)[, 1L]
     any(vapply(possible, function(possBlock) tryChars(chars, pos + 1, used, possBlock), logical(1)))
   }
 }
 setNames(vapply(charList, tryChars, logical(1), 1L, used), x)

} canMake(c("A",

          "BARK",
          "BOOK",
          "TREAT",
          "COMMON",
          "SQUAD",
          "CONFUSE"))</lang>
Output:
      A    BARK    BOOK   TREAT  COMMON   SQUAD CONFUSE 
   TRUE    TRUE   FALSE    TRUE   FALSE    TRUE    TRUE

Without recursion

Second version without recursion and giving every unique combination of blocks for each word: <lang R>canMakeNoRecursion <- function(x) {

 x <- toupper(x)
 charList <- strsplit(x, character(0))
 getCombos <- function(chars) {
   charBlocks <-  data.matrix(expand.grid(lapply(chars, function(char) which(blocks == char, arr.ind=TRUE)[, 1L])))
   charBlocks <- charBlocks[!apply(charBlocks, 1, function(row) any(duplicated(row))), , drop=FALSE]
   if (dim(charBlocks)[1L] > 0L) {
     t(apply(charBlocks, 1, function(row) apply(blocks[row, , drop=FALSE], 1, paste, collapse="")))
   } else {
     character(0)
   }
 }
 setNames(lapply(charList, getCombos), x)

} canMakeNoRecursion(c("A",

          "BARK",
          "BOOK",
          "TREAT",
          "COMMON",
          "SQUAD",
          "CONFUSE"))</lang>
Output:
$A
     [,1] [,2]
[1,] "AN" "NA"

$BARK
     [,1] [,2] [,3] [,4]
[1,] "BO" "AN" "RE" "XK"
[2,] "OB" "AN" "RE" "XK"
[3,] "BO" "NA" "RE" "XK"
[4,] "OB" "NA" "RE" "XK"
[5,] "BO" "AN" "ER" "XK"
[6,] "OB" "AN" "ER" "XK"
[7,] "BO" "NA" "ER" "XK"
[8,] "OB" "NA" "ER" "XK"

$BOOK
character(0)

$TREAT
     [,1] [,2] [,3] [,4] [,5]
[1,] "GT" "RE" "ER" "AN" "TG"
[2,] "GT" "ER" "RE" "AN" "TG"
[3,] "GT" "RE" "ER" "NA" "TG"
[4,] "GT" "ER" "RE" "NA" "TG"
[5,] "TG" "RE" "ER" "AN" "GT"
[6,] "TG" "ER" "RE" "AN" "GT"
[7,] "TG" "RE" "ER" "NA" "GT"
[8,] "TG" "ER" "RE" "NA" "GT"

$COMMON
character(0)

$SQUAD
     [,1] [,2] [,3] [,4] [,5]
[1,] "FS" "QD" "HU" "AN" "DQ"
[2,] "FS" "QD" "HU" "AN" "DQ"
[3,] "FS" "QD" "HU" "NA" "DQ"
[4,] "FS" "QD" "HU" "NA" "DQ"
[5,] "FS" "DQ" "HU" "AN" "QD"
[6,] "FS" "DQ" "HU" "AN" "QD"
[7,] "FS" "DQ" "HU" "NA" "QD"
[8,] "FS" "DQ" "HU" "NA" "QD"

$CONFUSE
      [,1] [,2] [,3] [,4] [,5] [,6] [,7]
 [1,] "CP" "OB" "NA" "FS" "HU" "FS" "ER"
 [2,] "PC" "OB" "NA" "FS" "HU" "FS" "ER"
 [3,] "CP" "BO" "NA" "FS" "HU" "FS" "ER"
 [4,] "PC" "BO" "NA" "FS" "HU" "FS" "ER"
 [5,] "CP" "OB" "AN" "FS" "HU" "FS" "ER"
 [6,] "PC" "OB" "AN" "FS" "HU" "FS" "ER"
 [7,] "CP" "BO" "AN" "FS" "HU" "FS" "ER"
 [8,] "PC" "BO" "AN" "FS" "HU" "FS" "ER"
 [9,] "CP" "OB" "NA" "FS" "HU" "FS" "ER"
[10,] "PC" "OB" "NA" "FS" "HU" "FS" "ER"
[11,] "CP" "BO" "NA" "FS" "HU" "FS" "ER"
[12,] "PC" "BO" "NA" "FS" "HU" "FS" "ER"
[13,] "CP" "OB" "AN" "FS" "HU" "FS" "ER"
[14,] "PC" "OB" "AN" "FS" "HU" "FS" "ER"
[15,] "CP" "BO" "AN" "FS" "HU" "FS" "ER"
[16,] "PC" "BO" "AN" "FS" "HU" "FS" "ER"
[17,] "CP" "OB" "NA" "FS" "HU" "FS" "RE"
[18,] "PC" "OB" "NA" "FS" "HU" "FS" "RE"
[19,] "CP" "BO" "NA" "FS" "HU" "FS" "RE"
[20,] "PC" "BO" "NA" "FS" "HU" "FS" "RE"
[21,] "CP" "OB" "AN" "FS" "HU" "FS" "RE"
[22,] "PC" "OB" "AN" "FS" "HU" "FS" "RE"
[23,] "CP" "BO" "AN" "FS" "HU" "FS" "RE"
[24,] "PC" "BO" "AN" "FS" "HU" "FS" "RE"
[25,] "CP" "OB" "NA" "FS" "HU" "FS" "RE"
[26,] "PC" "OB" "NA" "FS" "HU" "FS" "RE"
[27,] "CP" "BO" "NA" "FS" "HU" "FS" "RE"
[28,] "PC" "BO" "NA" "FS" "HU" "FS" "RE"
[29,] "CP" "OB" "AN" "FS" "HU" "FS" "RE"
[30,] "PC" "OB" "AN" "FS" "HU" "FS" "RE"
[31,] "CP" "BO" "AN" "FS" "HU" "FS" "RE"
[32,] "PC" "BO" "AN" "FS" "HU" "FS" "RE"

Racket

I believe you can make an empty word by using no blocks. So '(can-make-word? "")' is true for me.

<lang racket>#lang racket (define block-strings

 (list "BO" "XK" "DQ" "CP" "NA"
       "GT" "RE" "TG" "QD" "FS"
       "JW" "HU" "VI" "AN" "OB"
       "ER" "FS" "LY" "PC" "ZM"))

(define BLOCKS (map string->list block-strings))

(define (can-make-word? w)

 (define (usable-block blocks word-char)
   (for/first ((b (in-list blocks)) #:when (memf (curry char-ci=? word-char) b)) b))
 
 (define (inner word-chars blocks tried-blocks)
   (cond
     [(null? word-chars) #t]
     [(usable-block blocks (car word-chars))
      =>
      (lambda (b)
        (or
         (inner (cdr word-chars) (append tried-blocks (remove b blocks)) null)
         (inner word-chars (remove b blocks) (cons b tried-blocks))))]
     [else #f]))
 (inner (string->list w) BLOCKS null))

(define WORD-LIST '("" "A" "BARK" "BOOK" "TREAT" "COMMON" "SQUAD" "CONFUSE")) (define (report-word w)

 (printf "Can we make: ~a? ~a~%"
         (~s w #:min-width 9)
         (if (can-make-word? w) "yes" "no")))

(module+ main

 (for-each report-word WORD-LIST))  

(module+ test

 (require rackunit)
 (check-true  (can-make-word? ""))
 (check-true  (can-make-word? "A"))
 (check-true  (can-make-word? "BARK"))
 (check-false (can-make-word? "BOOK"))
 (check-true  (can-make-word? "TREAT"))
 (check-false (can-make-word? "COMMON"))
 (check-true  (can-make-word? "SQUAD"))
 (check-true  (can-make-word? "CONFUSE")))</lang>
Output:
Can we make: ""       ? yes
Can we make: "A"      ? yes
Can we make: "BARK"   ? yes
Can we make: "BOOK"   ? no
Can we make: "TREAT"  ? yes
Can we make: "COMMON" ? no
Can we make: "SQUAD"  ? yes
Can we make: "CONFUSE"? yes

RapidQ

<lang vb>dim Blocks as string dim InWord as string

Function CanMakeWord (FInWord as string, FBlocks as string) as integer

   dim WIndex as integer, BIndex as integer
   
   FBlocks = UCase$(FBlocks) - " " - ","
   FInWord = UCase$(FInWord)
   
   for WIndex = 1 to len(FInWord)
       BIndex = instr(FBlocks, FInWord[WIndex])
       
       if BIndex then
           FBlocks = Replace$(FBlocks,"**",iif(BIndex mod 2,BIndex,BIndex-1))
       else
           Result = 0
           exit function
       end if
   next
   
   Result = 1            

end function

InWord = "Confuse" Blocks = "BO, XK, DQ, CP, NA, GT, RE, TG, QD, FS, JW, HU, VI, AN, OB, ER, FS, LY, PC, ZM" showmessage "Can make: " + InWord + " = " + iif(CanMakeWord(InWord, Blocks), "True", "False") </lang>

Output:
Can make: A = TRUE
Can make: BARK = TRUE
Can make: BOOK = FALSE
Can make: TREAT = TRUE
Can make: COMMON = FALSE
Can make: SQUAD = TRUE
Can make: CONFUSE = TRUE

REXX

version 1

<lang rexx>/*REXX pgm finds if words can be spelt from a pool of toy blocks (each having 2 letters)*/ list= 'A bark bOOk treat common squaD conFuse' /*words can be: upper/lower/mixed case*/ blocks= 'BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM' upper blocks; do k=1 for words(list) /*traipse through a list of some words.*/

                   call  spell  word(list, k)   /*display if word can be spelt (or not)*/
                   end   /*k*/                  /* [↑]  tests each word in the list.   */

exit /*stick a fork in it, we're all done. */ /*──────────────────────────────────────────────────────────────────────────────────────*/ spell: procedure expose blocks; arg x /*ARG uppercases the word to be spelt.*/

                        L=length(x);    @.=0    /*get length of the word to be spelt.  */
          do try=1  for L;  z=blocks            /*use a fresh copy of the  "Z"  blocks.*/
            do n=1  for L;  y=substr(x, n, 1)   /*attempt another letter in the word.  */
            @.n=pos(y, z, 1+@.n);    if @.n==0  then leave     /*not found?  Try again.*/
            z=overlay(' ', z, @.n)              /*mutate the toy block  ───►  a onesy. */
               do q=1  for words(blocks);  if length(word(z,q))==1  then z=delword(z,q,1)
               end   /*q*/                      /* [↑]  elide any existing onesy block.*/
            if n==L  then leave try             /*was last letter used in the spelling?*/
            end      /*n*/                      /* [↑]  end of a  toy block  usage.    */
          end        /*try*/                    /* [↑]  end of a  "TRY"  permute.      */
      say right(arg(1), 30)     right( word( "can't can", (n==L) +1), 6)      'be spelt.'
      return</lang>

output:     [Spelling note:   "spelt" is an alternate version of "spelled".]

                             A    can be spelt.
                          bark    can be spelt.
                          bOOk  can't be spelt.
                         treat    can be spelt.
                        common  can't be spelt.
                         squaD    can be spelt.
                       conFuse    can be spelt.  

version 2

<lang rexx>/* REXX ---------------------------------------------------------------

  • 10.01.2014 Walter Pachl counts the number of possible ways
  • 12.01.2014 corrected date and output
  • --------------------------------------------------------------------*/

show=(arg(1)<>) blocks = 'BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM' list = '$ A baRk bOOk trEat coMMon squaD conFuse' list=translate(list) Do i=1 To words(blocks)

 blkn.i=word(blocks,i)'-'i
 blk.i=word(blocks,i)
 End

w.= wlen=0 Do i=1 To words(list)

 w.i=word(list,i)
 wlen=max(wlen,length(w.i))
 End

Do wi=0 To words(list)

 word = w.wi
 ways=0
 poss.=0
 lw=length(word)
 cannot=0
 Do i=1 To lw                         /* loop over the characters   */
   c=substr(word,i,1)                 /* the current character      */
   Do j=1 To words(blocks)            /* loop over blocks           */
     blk=word(blocks,j)
     If pos(c,blk)>0 Then Do  /* block can be used in this position */
       z=poss.i.0+1
       poss.i.z=j
       poss.i.0=z            /* number of possible blocks for pos i */
       End
     End
   If poss.i.0=0 Then Do
     cannot=1
     Leave i
     End
   End
 If cannot=0 Then Do                  /* no prohibitive character   */
   s.=0
   Do j=1 To poss.1.0          /* build possible strings for char 1 */
     z=s.1.0+1
     s.1.z=poss.1.j
     s.1.0=z
     End
   Do i=2 To lw          /* build possible strings for chars 1 to i */
     ii=i-1
     Do j=1 To poss.i.0
       Do k=1 To s.ii.0
         z=s.i.0+1
         s.i.z=s.ii.k poss.i.j
         s.i.0=z
         End
       End
     End
   Do p=1 To s.lw.0            /* loop through all possible strings */
     v=valid(s.lw.p)                  /* test if the string is valid*/
     If v Then Do                     /* it is                      */
       ways=ways+1                    /* increment number of ways   */
       way.ways=                 /* and store the string's blocks */
       Do ii=1 To lw
         z=word(s.lw.p,ii)
         way.ways=way.ways blk.z
         End
       End
     End
   End

/*---------------------------------------------------------------------

  • now show the result
  • --------------------------------------------------------------------*/
 ol=left('word',wlen+2)
 Select
   When ways=0 Then
     ol=ol 'cannot be spelt'
   When ways=1 Then
     ol=ol 'can be spelt'
   Otherwise
     ol=ol 'can be spelt in' ways 'ways'
   End
 Say ol'.'
 If show Then Do
   Do wj=1 To ways
     Say copies(' ',10) way.wj
     End
   End
 End

Exit

valid: Procedure /*---------------------------------------------------------------------

  • Check if the same block is used more than once -> 0
  • Else: the combination is valid
  • --------------------------------------------------------------------*/
 Parse Arg list
 used.=0
 Do i=1 To words(list)
   w=word(list,i)
   If used.w Then Return 0
   used.w=1
   End
 Return 1</lang>
Output:
''        cannot be spelt.
'$'       cannot be spelt.
'A'       can be spelt in 2 ways.
'BARK'    can be spelt in 8 ways.
'BOOK'    cannot be spelt.
'TREAT'   can be spelt in 8 ways.
'COMMON'  cannot be spelt.
'SQUAD'   can be spelt in 8 ways.
'CONFUSE' can be spelt in 32 ways.
Output:

extended

''        cannot be spelt.
'$'       cannot be spelt.
'A'       can be spelt in 2 ways.
            NA
            AN
'BARK'    can be spelt in 8 ways.
            BO NA RE XK
            OB NA RE XK
            BO AN RE XK
            OB AN RE XK
            BO NA ER XK
            OB NA ER XK
            BO AN ER XK
            OB AN ER XK
'BOOK'    cannot be spelt.
'TREAT'   can be spelt in 8 ways.
            TG ER RE NA GT
            TG RE ER NA GT
            TG ER RE AN GT
            TG RE ER AN GT
            GT ER RE NA TG
            GT RE ER NA TG
            GT ER RE AN TG
            GT RE ER AN TG
'COMMON'  cannot be spelt.
'SQUAD'   can be spelt in 8 ways.
            FS QD HU NA DQ
            FS QD HU NA DQ
            FS QD HU AN DQ
            FS QD HU AN DQ
            FS DQ HU NA QD
            FS DQ HU NA QD
            FS DQ HU AN QD
            FS DQ HU AN QD
'CONFUSE' can be spelt in 32 ways.
            CP BO NA FS HU FS RE
            PC BO NA FS HU FS RE
            CP OB NA FS HU FS RE
            PC OB NA FS HU FS RE
            CP BO AN FS HU FS RE
            PC BO AN FS HU FS RE
            CP OB AN FS HU FS RE
            PC OB AN FS HU FS RE
            CP BO NA FS HU FS RE
            PC BO NA FS HU FS RE
            CP OB NA FS HU FS RE
            PC OB NA FS HU FS RE
            CP BO AN FS HU FS RE
            PC BO AN FS HU FS RE
            CP OB AN FS HU FS RE
            PC OB AN FS HU FS RE
            CP BO NA FS HU FS ER
            PC BO NA FS HU FS ER
            CP OB NA FS HU FS ER
            PC OB NA FS HU FS ER
            CP BO AN FS HU FS ER
            PC BO AN FS HU FS ER
            CP OB AN FS HU FS ER
            PC OB AN FS HU FS ER
            CP BO NA FS HU FS ER
            PC BO NA FS HU FS ER
            CP OB NA FS HU FS ER
            PC OB NA FS HU FS ER
            CP BO AN FS HU FS ER
            PC BO AN FS HU FS ER
            CP OB AN FS HU FS ER
            PC OB AN FS HU FS ER

Ring

<lang ring>Blocks = [ :BO, :XK, :DQ, :CP, :NA, :GT, :RE, :TG, :QD, :FS, :JW, :HU, :VI, :AN, :OB, :ER, :FS, :LY, :PC, :ZM ] Words = [ :A, :BARK, :BOOK, :TREAT, :COMMON, :SQUAD, :CONFUSE ]

for x in words see '>>> can_make_word("' + upper(x) + '")' + nl if checkword(x,blocks) see "True" + nl else see "False" + nl ok next

func CheckWord Word,Blocks cBlocks = BLocks for x in word Found = false for y = 1 to len(cblocks) if x = cblocks[y][1] or x = cblocks[y][2] cblocks[y] = "--" found = true exit ok next if found = false return false ok next return true</lang>

Output:
>>> can_make_word("A")
True
>>> can_make_word("BARK")
True
>>> can_make_word("BOOK")
False
>>> can_make_word("TREAT")
True
>>> can_make_word("COMMON")
False
>>> can_make_word("SQUAD")
True
 >>> can_make_word("CONFUSE")
True

Ruby

This one uses a case insensitive regular expression. The 'sub!' method substitutes the first substring it finds and returns nil if nothing is found. <lang ruby>words = %w(A BaRK BOoK tREaT COmMOn SqUAD CoNfuSE) << ""

words.each do |word|

 blocks = "BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM"
 res = word.each_char.all?{|c| blocks.sub!(/\w?#{c}\w?/i, "")}  #regexps can be interpolated like strings
 puts "#{word.inspect}: #{res}"

end </lang>

Output:
"A": true
"BaRK": true
"BOoK": false
"tREaT": true
"COmMOn": false
"SqUAD": true
"CoNfuSE": true
"": true

Run BASIC

<lang unbasic>blocks$ = "BO,XK,DQ,CP,NA,GT,RE,TG,QD,FS,JW,HU,VI,AN,OB,ER,FS,LY,PC,ZM" makeWord$ = "A,BARK,BOOK,TREAT,COMMON,SQUAD,Confuse" b = int((len(blocks$) /3) + 1) dim blk$(b)

for i = 1 to len(makeWord$)

 wrd$ = word$(makeWord$,i,",")
 dim hit(b)
 n = 0
 if wrd$ = "" then exit for
 for k = 1 to len(wrd$)
   w$ = upper$(mid$(wrd$,k,1))
   for j = 1 to b
    if hit(j) = 0 then
     if w$ = left$(word$(blocks$,j,","),1) or w$ = right$(word$(blocks$,j,","),1) then
       hit(j) = 1
       n = n + 1
       exit for
     end if
    end if
   next j
 next k
 print wrd$;chr$(9);
 if n = len(wrd$) then print " True" else print " False"

next i</lang>

A	 True
BARK	 True
BOOK	 False
TREAT	 True
COMMON	 False
SQUAD	 True
Confuse	 True

Rust

This implementation uses a backtracking search. <lang rust>use std::iter::repeat;

fn rec_can_make_word(index: usize, word: &str, blocks: &[&str], used: &mut[bool]) -> bool {

   let c = word.chars().nth(index).unwrap().to_uppercase().next().unwrap();
   for i in 0..blocks.len() {
       if !used[i] && blocks[i].chars().any(|s| s == c) {
           used[i] = true;
           if index == 0 || rec_can_make_word(index - 1, word, blocks, used) {
               return true;
           }
           used[i] = false;
       }
   }
   false

}

fn can_make_word(word: &str, blocks: &[&str]) -> bool {

   return rec_can_make_word(word.chars().count() - 1, word, blocks, 
                            &mut repeat(false).take(blocks.len()).collect::<Vec<_>>());

}

fn main() {

   let blocks = [("BO"), ("XK"), ("DQ"), ("CP"), ("NA"), ("GT"), ("RE"), ("TG"), ("QD"), ("FS"), 
                 ("JW"), ("HU"), ("VI"), ("AN"), ("OB"), ("ER"), ("FS"), ("LY"), ("PC"), ("ZM")];
   let words = ["A", "BARK", "BOOK", "TREAT", "COMMON", "SQUAD", "CONFUSE"];
   for word in &words {
       println!("{} -> {}", word, can_make_word(word, &blocks))
   }

} </lang>

Output:
A -> true
BARK -> true
BOOK -> false
TREAT -> true
COMMON -> false
SQUAD -> true
CONFUSE -> true

Scala

Library: Scala

<lang Scala>object AbcBlocks extends App {

 protected class Block(face1: Char, face2: Char) {
   def isFacedWith(that: Char) = { that == face1 || that == face2 }
   override def toString() = face1.toString + face2
 }
 protected object Block {
   def apply(faces: String) = new Block(faces.head, faces.last)
 }
 type word = Seq[Block]
 private val blocks = List(Block("BO"), Block("XK"), Block("DQ"), Block("CP"), Block("NA"),
   Block("GT"), Block("RE"), Block("TG"), Block("QD"), Block("FS"),
   Block("JW"), Block("HU"), Block("VI"), Block("AN"), Block("OB"),
   Block("ER"), Block("FS"), Block("LY"), Block("PC"), Block("ZM"))
 private def isMakeable(word: String, blocks: word) = {
   def getTheBlocks(word: String, blocks: word) = {
     def inner(word: String, toCompare: word, rest: word, accu: word): word = {
       if (word.isEmpty || rest.isEmpty || toCompare.isEmpty) accu
       else if (toCompare.head.isFacedWith(word.head)) {
         val restant = rest diff List(toCompare.head)
         inner(word.tail, restant, restant, accu :+ toCompare.head)
       } else inner(word, toCompare.tail, rest, accu)
     }
     inner(word, blocks, blocks, Nil)
   }
   word.lengthCompare(getTheBlocks(word, blocks).size) == 0
 }
 val words = List("A", "BARK", "BOOK", "TREAT", "COMMON", "SQUAD", "CONFUSED", "ANBOCPDQERSFTGUVWXLZ")
 // Automatic tests
 assert(isMakeable(words(0), blocks))
 assert(isMakeable(words(1), blocks))
 assert(!isMakeable(words(2), blocks)) // BOOK not
 assert(isMakeable(words(3), blocks))
 assert(!isMakeable(words(4), blocks)) // COMMON not
 assert(isMakeable(words(5), blocks))
 assert(isMakeable(words(6), blocks))
 assert(isMakeable(words(7), blocks))
 //words(7).mkString.permutations.foreach(s => assert(isMakeable(s, blocks)))
 words.foreach(w => println(s"$w can${if (isMakeable(w, blocks)) " " else "not "}be made."))

}</lang>

Scheme

In R5RS: <lang scheme>(define *blocks*

 '((#\B #\O) (#\X #\K) (#\D #\Q) (#\C #\P) (#\N #\A)
   (#\G #\T) (#\R #\E) (#\T #\G) (#\Q #\D) (#\F #\S)
   (#\J #\W) (#\H #\U) (#\V #\I) (#\A #\N) (#\O #\B)
   (#\E #\R) (#\F #\S) (#\L #\Y) (#\P #\C) (#\Z #\M)))

(define (exists p? li)

 (and (not (null? li))
      (or (p? (car li))
          (exists p? (cdr li)))))

(define (remove-one x li)

 (cond
   ((null? li) '())
   ((equal? (car li) x) (cdr li))
   (else (cons (car li) (remove-one x (cdr li))))))

(define (can-make-list? li blocks)

 (or (null? li)
     (exists
      (lambda (block)
        (and
         (member (char-upcase (car li)) block)
         (can-make-list? (cdr li) (remove-one block blocks))))
      blocks)))

(define (can-make-word? word)

 (can-make-list? (string->list word) *blocks*))


(define *words*

 '("A" "Bark" "book" "TrEaT" "COMMON" "squaD" "CONFUSE"))

(for-each

(lambda (word)
  (display (if (can-make-word? word)
               "   Can make word: "
               "Cannot make word: "))
  (display word)
  (newline))
*words*)</lang>
Output:
   Can make word: A
   Can make word: Bark
Cannot make word: book
   Can make word: TrEaT
Cannot make word: COMMON
   Can make word: squaD
   Can make word: CONFUSE

Seed7

<lang seed7>$ include "seed7_05.s7i";

const func boolean: canMakeWords (in array string: blocks, in string: word) is func

 result
   var boolean: okay is FALSE;
 local
   var integer: index is 1;
 begin
   if word = "" then
     okay := TRUE;
   elsif length(blocks) <> 0 then
     while index <= length(blocks) and not okay do
       if blocks[index][1] = word[1] or blocks[index][2] = word[1] then
         okay := canMakeWords(blocks[.. pred(index)] & blocks[succ(index) ..], word[2 ..]);
       end if;
       incr(index);
     end while;
   end if;
 end func;

const array string: blocks is [] ("BO", "XK", "DQ", "CP", "NA", "GT", "RE", "TG", "QD", "FS",

                                 "JW", "HU", "VI", "AN", "OB", "ER", "FS", "LY", "PC", "ZM");

const func boolean: canMakeWords (in string: word) is

 return canMakeWords(blocks, upper(word));

const proc: main is func

 local
   var string: word is "";
 begin
   for word range [] ("", "A", "BARK", "BOOK", "TREAT", "COMMON", "SQUAD", "Confuse") do
     writeln(word rpad 10 <& canMakeWords(word));
   end for;
 end func;</lang>
Output:
          TRUE
A         TRUE
BARK      TRUE
BOOK      FALSE
TREAT     TRUE
COMMON    FALSE
SQUAD     TRUE
Confuse   TRUE

SequenceL

Recursive Search Version

<lang sequencel>import <Utilities/Conversion.sl>; import <Utilities/Sequence.sl>;

main(args(2)) := let result[i] := args[i] ++ ": " ++ boolToString(can_make_word(args[i], InitBlocks)); in delimit(result, '\n');

InitBlocks := ["BO", "XK", "DQ", "CP", "NA", "GT", "RE", "TG", "QD", "FS", "JW", "HU", "VI", "AN", "OB", "ER", "FS", "LY", "PC", "ZM"];

can_make_word(word(1), blocks(2)) := let choices[i] := i when some(blocks[i] = toUpper(head(word))); blocksAfterChoice[i] := blocks[(1 ... (choices[i] - 1)) ++ ((choices[i] + 1) ... size(blocks))]; in true when size(word) = 0 else false when size(choices) = 0 else some(can_make_word(tail(word), blocksAfterChoice));

toUpper(letter(0)) := let ascii := asciiToInt(letter); in letter when ascii >= 65 and ascii <= 90 else intToAscii(ascii - 32);</lang>

Output:
cmd:> main.exe A BARK BOOK TREAT COMMON SQUAD CONFUSE
"A: true
BARK: true
BOOK: false
TREAT: true
COMMON: false
SQUAD: true
CONFUSE: true"

RegEx Version

<lang sequencel>import <Utilities/Conversion.sl>; import <Utilities/Sequence.sl>; import <RegEx/RegEx.sl>;

main(args(2)) := let result[i] := args[i] ++ ": " ++ boolToString(can_make_word(args[i], InitBlocks)); in delimit(result, '\n');

InitBlocks := "BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM";

can_make_word(word(1), blocks(1)) := let regEx := "(\\a" ++ [toUpper(head(word))] ++ "|" ++ [toUpper(head(word))] ++ "\\a)";

newBlocks := replaceFirst(blocks, regEx, ""); in true when size(word) = 0 else false when size(newBlocks) = size(blocks) else can_make_word(tail(word), newBlocks);

toUpper(letter(0)) := let ascii := asciiToInt(letter); in letter when ascii >= 65 and ascii <= 90 else intToAscii(ascii - 32);</lang>

Sidef

Translation of: Perl

<lang ruby>func can_make_word(word, blocks) {

   blocks.map! { |b| b.uc.chars.sort.join }.freq!
   func(word, blocks) {
       var char = word.shift
       var candidates = blocks.keys.grep { |k| 0 <= k.index(char) }
       for candidate in candidates {
           blocks{candidate} <= 0 && next;
           local blocks{candidate} = (blocks{candidate} - 1);
           return true if (word.is_empty || __FUNC__(word, blocks));
       }
       return false;
   }(word.uc.chars, blocks)

}</lang>

Tests: <lang ruby>var b1 = %w(BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM) var b2 = %w(US TZ AO QA)

var tests = [

   ["A", true, b1],
   ["BARK", true, b1],
   ["BOOK", false, b1],
   ["TREAT", true, b1],
   ["COMMON", false, b1],
   ["SQUAD", true, b1],
   ["CONFUSE", true, b1],
   ["auto", true, b2],

];

tests.each { |t|

   var bool = can_make_word(t[0], t[2]);
   say ("%7s -> %s" % (t[0], bool));
   assert(bool == t[1])

}</lang>

Output:
      A -> true
   BARK -> true
   BOOK -> false
  TREAT -> true
 COMMON -> false
  SQUAD -> true
CONFUSE -> true
   auto -> true

Smalltalk

Recursive solution. Tested in Pharo. <lang smalltalk> ABCPuzzle>>test #('A' 'BARK' 'BOOK' 'TreaT' 'COMMON' 'sQUAD' 'CONFuSE') do: [ :each | Transcript crShow: each, ': ', (self solveFor: each) asString ]

ABCPuzzle>>solveFor: letters | blocks | blocks := #('BO' 'XK' 'DQ' 'CP' 'NA' 'GT' 'RE' 'TG' 'QD' 'FS' 'JW' 'HU' 'VI' 'AN' 'OB' 'ER' 'FS' 'LY' 'PC' 'ZM'). ^ self solveFor: letters asUppercase with: blocks asOrderedCollection

ABCPuzzle>>solveFor: letters with: blocks | l ldash matches | letters isEmpty ifTrue: [ ^ true ]. l := letters first. ldash := letters allButFirst. matches := blocks select: [ :b | b includes: l ]. matches isEmpty ifTrue: [ ^ false ]. matches do: [ :m | | bdash | bdash := blocks copy. bdash remove: m. (self solveFor: ldash with: bdash) ifTrue: [ ^ true ] ]. ^ false </lang>

Output:
ABCPuzzle new test

A: true
BARK: true
BOOK: false
TreaT: true
COMMON: false
sQUAD: true
CONFuSE: true

SPAD

<lang SPAD> blocks:List Tuple Symbol:= _

 [(B,O),(X,K),(D,Q),(C,P),(N,A),(G,T),(R,E),(T,G),(Q,D),(F,S), _
  (J,W),(H,U),(V,I),(A,N),(O,B),(E,R),(F,S),(L,Y),(P,C),(Z,M)]
         

findComb(l:List List NNI):List List NNI ==

 #l=0 => []
 #l=1 => [[s] for s in first l]
 r:List List NNI:=[]
 for y in findComb(rest l) repeat
   r:=concat(r,[concat(x,y) for x in first l])
 return r

canMakeWord?(word,blocks) ==

 word:=upperCase word
 bchr:=[map(char,map(string,s::List(Symbol))) for s in blocks]  
 c:=[[j for j in 1..#blocks | member?(word.k,bchr.j)] for k in 1..#word]
 reduce(_or,[test(#removeDuplicates(l)=#word) for l in findComb(c)])
 
 

Example:=["a","bark","book","treat","common","squad","confuse"]

[canMakeWord?(s,blocks) for s in Example]

</lang>

Programming details:UserGuide

Output:

  [true,true,false,true,false,true,true]
                                                     Type: List(Boolean) 

There is optimization potential of course.


Swift

<lang Swift>import Foundation

func Blockable(str: String) -> Bool {

   var blocks = [
       "BO", "XK", "DQ", "CP", "NA", "GT", "RE", "TG", "QD", "FS",
       "JW", "HU", "VI", "AN", "OB", "ER", "FS", "LY", "PC", "ZM" ]
   var strUp = str.uppercaseString
   var final = ""
   for char: Character in strUp {
       var CharString: String = ""; CharString.append(char)
       for j in 0..<blocks.count {
           if blocks[j].hasPrefix(CharString) ||
              blocks[j].hasSuffix(CharString) {
               final.append(char)
               blocks[j] = ""
               break
           }
       }
   }
   return final == strUp

}

func CanOrNot(can: Bool) -> String {

   return can ? "can" : "cannot"

}

for str in [ "A", "BARK", "BooK", "TrEaT", "comMON", "sQuAd", "Confuse" ] {

   println("'\(str)' \(CanOrNot(Blockable(str))) be spelled with blocks.")

}</lang>

Output:
'A' can be spelled with blocks.
'BARK' can be spelled with blocks.
'BooK' cannot be spelled with blocks.
'TrEaT' can be spelled with blocks.
'comMON' cannot be spelled with blocks.
'sQuAd' can be spelled with blocks.
'Confuse' can be spelled with blocks.
Works with: Swift version 3.0.2

<lang Swift>import Swift

func canMake(word: String) -> Bool { var blocks = [ "BO", "XK", "DQ", "CP", "NA", "GT", "RE", "TG", "QD", "FS", "JW", "HU", "VI", "AN", "OB", "ER", "FS", "LY", "PC", "ZM" ]

for letter in word.uppercased().characters { guard let index = blocks.index(where: { $0.characters.contains(letter) }) else { return false }

blocks.remove(at: index) }

return true }

let words = ["a", "bARK", "boOK", "TreAt", "CoMmon", "SquAd", "CONFUse"]

words.forEach { print($0, canMake(word: $0)) }</lang>

Output:
A true
BARK true
BooK false
TrEaT true
comMON false
sQuAd true
Confuse true

Tcl

Works with: Tcl version 8.6

<lang tcl>package require Tcl 8.6

proc abc {word {blocks {BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM}}} {

   set abc {{letters blocks abc} {

set rest [lassign $letters ch] set i 0 foreach blk $blocks { if {$ch in $blk && (![llength $rest] || [apply $abc $rest [lreplace $blocks $i $i] $abc])} { return true } incr i } return false

   }}
   return [apply $abc [split $word ""] [lmap b $blocks {split $b ""}] $abc]

}

foreach word {"" A BARK BOOK TREAT COMMON SQUAD CONFUSE} {

   puts [format "Can we spell %9s? %s" '$word' [abc $word]]

}</lang>

Output:
Can we spell        ''? false
Can we spell       'A'? true
Can we spell    'BARK'? true
Can we spell    'BOOK'? false
Can we spell   'TREAT'? true
Can we spell  'COMMON'? false
Can we spell   'SQUAD'? true
Can we spell 'CONFUSE'? true

TUSCRIPT

<lang tuscript>set words = "A'BARK'BOOK'TREAT'COMMON'SQUAD'CONFUSE" set result = * loop word = words

  set blocks = "BO'XK'DQ'CP'NA'GT'RE'TG'QD'FS'JW'HU'VI'AN'OB'ER'FS'LY'PC'ZM"
  set wordx = split (word, |"~</~")
  set cond = "true"
  loop char = wordx
     set n = filter_index (blocks, "~*{char}*~", -)
     if (n.eq."") then
        set cond = "false"
        exit
     endif
     set n2 = select (n, 1)
     set n3 = select (blocks, #n2, blocks)
  endloop
  set out = concat (word, " ", cond)
  set result = append (result, out)

endloop</lang>

Output:
A true
BARK true
BOOK false
TREAT true
COMMON false
SQUAD true
CONFUSE true

TXR

<lang txr>@(do

  (defvar blocks '((B O) (X K) (D Q) (C P) (N A) (G T) (R E) (T G)
                   (Q D) (F S) (J W) (H U) (V I) (A N) (O B) (E R)
                   (F S) (L Y) (P C) (Z M)))
  ;; Define and build hash which maps each letter that occurs in blocks
  ;; to a list of the blocks in which that letter occurs.
  (defvar alpha2blocks [hash-uni [group-by first blocks]
                                 [group-by second blocks]
                                 append])
  ;; convert, e.g. "abc" -> (A B C)
  ;; intern -- convert a string to an interned symbol "A" -> A
  ;; tuples -- turn string into 1-element tuples: "ABC" -> ("A" "B" "C")
  ;; square brackets around mapcar -- Lisp-1 style evaluation, allowing
  ;;   the intern function binding to be treated as a variable binding.
  (defun string-to-syms (str)
    [mapcar intern (tuples 1 (upcase-str str))])
  ;; Recursive part of algorithm working purely with Lisp symbols.
  ;; alpha -- single symbol denoting a letter
  ;; [alpha2blocks alpha] -- look up list of blocks for given letter
  ;; (memq item list) -- is item a member of list, under eq equality?
  ;; (remq item list) -- remove items from list which are eq to item.
  (defun can-make-word-guts (letters blocks)
    (cond
      ((null letters) t)
      ((null blocks) nil)
      (t (let ((alpha (first letters)))
           (each ((bl [alpha2blocks alpha]))
             (if (and (memq bl blocks)
                      (can-make-word-guts (rest letters)
                                          (remq bl blocks)))
               (return-from can-make-word-guts t)))))))
  (defun can-make-word (str)
    (can-make-word-guts (string-to-syms str) blocks)))

@(repeat) @w @(output) >>> can_make_word("@(upcase-str w)") @(if (can-make-word w) "True" "False") @(end) @(end)</lang>

Run:

$ cat abc-problem.data
a
bark
book
treat
common
squad
confuse
$ txr abc-problem.txr abc-problem.data
>>> can_make_word("A")
True
>>> can_make_word("BARK")
True
>>> can_make_word("BOOK")
False
>>> can_make_word("TREAT")
True
>>> can_make_word("COMMON")
False
>>> can_make_word("SQUAD")
True
>>> can_make_word("CONFUSE")
True

UNIX Shell

Works with: bash

<lang bash>can_build_word() {

   if $1 ; then
       can_build_word_rec "$1" BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM 
   else
       return 1
   fi

}

can_build_word_rec() {

   -z $1  && return 0
   local -u word=$1       # uppercase the first parameter
   shift
   local blocks=("$@")
   # see if we have a block for the first letter
   local letter=${word:0:1} indices=() i
   for (( i=0; i<${#blocks[@]}; i++ )); do
       if [[ ${blocks[i]} == *$letter* ]]; then
           indices+=($i)
       fi
   done
   (( ${#indices[@]} == 0 )) && return 1
   local tmp
   for i in ${indices[@]}; do
       tmp=( "${blocks[@]}" )
       unset "tmp[$i]"
       can_build_word_rec "${word:1}" "${tmp[@]}" && return 0
   done
   return 1

}

words=( "" A BARK Book treat COMMON Squad confuse ) for word in "${words[@]}"; do

   can_build_word "$word" "${blocks[@]}" && ans=yes || ans=no
   printf "%s\t%s\n" "$word" $ans

done</lang>

Output:
	no
A	yes
BARK	yes
Book	no
treat	yes
COMMON	no
Squad	yes
confuse	yes

zkl

Translation of: C

<lang zkl>var blocks=T("BO", "XK", "DQ", "CP", "NA", "GT", "RE", "TG", "QD", "FS", "JW", "HU", "VI", "AN", "OB", "ER", "FS", "LY", "PC", "ZM", );

fcn can_make_word(word){

  fcn(blks,word){
     if (not word) return(True);  // bottom of recursion
     foreach b in (blks){ n:=__bWalker.idx;

if(not b.holds(word[0])) continue; // letter not on this block blks.del(n); // remove this block from pile if (self.fcn(blks,word[1,*])) return(True); // try remaining blocks blks.insert(n,b); // put block back in pile: backtracking

     }
     False;   // out of blocks but not out of word
  }(blocks.copy(),word.toUpper())

}

foreach word in (T("","A","BarK","BOOK","TREAT","COMMON","SQUAD","Confuse","abba")){

  can_make_word(word).println(": ",word);

}</lang>

Output:
True: 
True: A
True: BarK
False: BOOK
True: TREAT
False: COMMON
True: SQUAD
True: Confuse
True: abba

ZX Spectrum Basic

<lang zxbasic>10 LET b$="BOXKDQCPNAGTRETGQDFSJWHUVIANOBERFSLYPCZM" 20 READ p 30 FOR c=1 TO p 40 READ p$ 50 GO SUB 100 60 NEXT c 70 STOP 80 DATA 7,"A","BARK","BOOK","TREAT","COMMON","SQUAD","CONFUSE" 90 REM Can make? 100 LET u$=b$ 110 PRINT "Can make word ";p$;"? "; 120 FOR i=1 TO LEN p$ 130 FOR j=1 TO LEN u$ 140 IF p$(i)=u$(j) THEN GO SUB 200: GO TO 160 150 NEXT j 160 IF j>LEN u$ THEN PRINT "No": RETURN 170 NEXT i 180 PRINT "Yes": RETURN 190 REM Erase pair 200 IF j/2=INT (j/2) THEN LET u$(j-1 TO j)=" ": RETURN 210 LET u$(j TO j+1)=" ": RETURN</lang>

Output:
Can make word A? Yes
Can make word BARK? Yes
Can make word BOOK? No
Can make word TREAT? Yes
Can make word COMMON? No
Can make word SQUAD? Yes
Can make word CONFYUSE? Yes