Determine if a string has all unique characters
You are encouraged to solve this task according to the task description, using any language you may know.
- Task
Given a character string (which may be empty, or have a length of zero characters):
- create a function/procedure/routine to:
- determine if all the characters in the string are unique
- indicate if or which character is duplicated and where
- display each string and its length (as the strings are being examined)
- a zero─length (empty) string shall be considered as unique
- process the strings from left─to─right
- if unique, display a message saying such
- if not unique, then:
- display a message saying such
- display what character is duplicated
- only the 1st non─unique character need be displayed
- display where "both" duplicated characters are in the string
- the above messages can be part of a single message
- display the hexadecimal value of the duplicated character
Use (at least) these five test values (strings):
- a string of length 0 (an empty string)
- a string of length 1 which is a single period (.)
- a string of length 6 which contains: abcABC
- a string of length 7 which contains a blank in the middle: XYZ ZYX
- a string of length 36 which doesn't contain the letter "oh":
- 1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ
Show all output here on this page.
- Related tasks
AWK
<lang AWK>
- syntax: GAWK -f DETERMINE_IF_A_STRING_HAS_ALL_UNIQUE_CHARACTERS.AWK
BEGIN {
for (i=0; i<=255; i++) { ord_arr[sprintf("%c",i)] = i } # build array[character]=ordinal_value
n = split(",.,abcABC,XYZ ZYX,1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ",arr,",")
for (i in arr) {
width = max(width,length(arr[i]))
}
width += 2
fmt = "| %-*s | %-6s | %-10s | %-8s | %-3s | %-9s |\n"
head1 = head2 = sprintf(fmt,width,"string","length","all unique","1st diff","hex","positions")
gsub(/[^|\n]/,"-",head1)
printf(head1 head2 head1) # column headings
for (i=1; i<=n; i++) {
main(arr[i])
}
printf(head1) # column footing
exit(0)
} function main(str, c,hex,i,leng,msg,position1,position2,tmp_arr) {
msg = "yes"
leng = length(str)
for (i=1; i<=leng; i++) {
c = substr(str,i,1)
if (c in tmp_arr) {
msg = "no"
first_diff = "'" c "'"
hex = sprintf("%2X",ord_arr[c])
position1 = index(str,c)
position2 = i
break
}
tmp_arr[c] = ""
}
printf(fmt,width,"'" str "'",leng,msg,first_diff,hex,position1 " " position2)
} function max(x,y) { return((x > y) ? x : y) } </lang>
- Output:
|----------------------------------------|--------|------------|----------|-----|-----------| | string | length | all unique | 1st diff | hex | positions | |----------------------------------------|--------|------------|----------|-----|-----------| | '' | 0 | yes | | | | | '.' | 1 | yes | | | | | 'abcABC' | 6 | yes | | | | | 'XYZ ZYX' | 7 | no | 'Z' | 5A | 3 5 | | '1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ' | 36 | no | '0' | 30 | 10 25 | |----------------------------------------|--------|------------|----------|-----|-----------|
C
In interactive mode, strings with spaces have to be enclosed in double quotes ("") <lang C>
- include<stdbool.h>
- include<string.h>
- include<stdlib.h>
- include<stdio.h>
typedef struct positionList{
int position; struct positionList *next;
}positionList;
typedef struct letterList{
char letter; int repititions; positionList* positions; struct letterList *next;
}letterList;
letterList* letterSet; bool duplicatesFound = false;
void checkAndUpdateLetterList(char c,int pos){
bool letterOccurs = false; letterList *letterIterator,*newLetter; positionList *positionIterator,*newPosition;
if(letterSet==NULL){
letterSet = (letterList*)malloc(sizeof(letterList));
letterSet->letter = c;
letterSet->repititions = 0;
letterSet->positions = (positionList*)malloc(sizeof(positionList));
letterSet->positions->position = pos;
letterSet->positions->next = NULL;
letterSet->next = NULL; }
else{
letterIterator = letterSet;
while(letterIterator!=NULL){
if(letterIterator->letter==c){
letterOccurs = true;
duplicatesFound = true;
letterIterator->repititions++;
positionIterator = letterIterator->positions;
while(positionIterator->next!=NULL)
positionIterator = positionIterator->next;
newPosition = (positionList*)malloc(sizeof(positionList));
newPosition->position = pos;
newPosition->next = NULL;
positionIterator->next = newPosition;
}
if(letterOccurs==false && letterIterator->next==NULL)
break;
else
letterIterator = letterIterator->next;
}
if(letterOccurs==false){
newLetter = (letterList*)malloc(sizeof(letterList));
newLetter->letter = c;
newLetter->repititions = 0;
newLetter->positions = (positionList*)malloc(sizeof(positionList));
newLetter->positions->position = pos;
newLetter->positions->next = NULL;
newLetter->next = NULL;
letterIterator->next = newLetter;
}
}
}
void printLetterList(){
positionList* positionIterator; letterList* letterIterator = letterSet;
while(letterIterator!=NULL){
if(letterIterator->repititions>0){
printf("\n'%c' (0x%x) at positions :",letterIterator->letter,letterIterator->letter);
positionIterator = letterIterator->positions;
while(positionIterator!=NULL){
printf("%3d",positionIterator->position + 1);
positionIterator = positionIterator->next;
}
}
letterIterator = letterIterator->next;
}
printf("\n");
}
int main(int argc,char** argv) {
int i,len;
if(argc>2){
printf("Usage : %s <Test string>\n",argv[0]);
return 0;
}
if(argc==1||strlen(argv[1])==1){
printf("\"%s\" - Length %d - Contains only unique characters.\n",argc==1?"":argv[1],argc==1?0:1);
return 0;
}
len = strlen(argv[1]);
for(i=0;i<len;i++){
checkAndUpdateLetterList(argv[1][i],i);
}
printf("\"%s\" - Length %d - %s",argv[1],len,duplicatesFound==false?"Contains only unique characters.\n":"Contains the following duplicate characters :");
if(duplicatesFound==true)
printLetterList();
return 0;
} </lang> Output, test strings from the task Determine_if_a_string_has_all_the_same_characters are also included :
abhishek_ghosh@Azure:~/doodles$ ./a.out "" - Length 0 - Contains only unique characters. abhishek_ghosh@Azure:~/doodles$ ./a.out . "." - Length 1 - Contains only unique characters. abhishek_ghosh@Azure:~/doodles$ ./a.out abcABC "abcABC" - Length 6 - Contains only unique characters. abhishek_ghosh@Azure:~/doodles$ ./a.out "XYZ YZX" "XYZ YZX" - Length 7 - Contains the following duplicate characters : 'X' (0x58) at positions : 1 7 'Y' (0x59) at positions : 2 5 'Z' (0x5a) at positions : 3 6 abhishek_ghosh@Azure:~/doodles$ ./a.out 1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ "1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ" - Length 36 - Contains the following duplicate characters : '0' (0x30) at positions : 10 25 abhishek_ghosh@Azure:~/doodles$ ./a.out " " " " - Length 3 - Contains the following duplicate characters : ' ' (0x20) at positions : 1 2 3 abhishek_ghosh@Azure:~/doodles$ ./a.out 2 "2" - Length 1 - Contains only unique characters. abhishek_ghosh@Azure:~/doodles$ ./a.out 333 "333" - Length 3 - Contains the following duplicate characters : '3' (0x33) at positions : 1 2 3 abhishek_ghosh@Azure:~/doodles$ ./a.out .55 ".55" - Length 3 - Contains the following duplicate characters : '5' (0x35) at positions : 2 3 abhishek_ghosh@Azure:~/doodles$ ./a.out tttTTT "tttTTT" - Length 6 - Contains the following duplicate characters : 't' (0x74) at positions : 1 2 3 'T' (0x54) at positions : 4 5 6 abhishek_ghosh@Azure:~/doodles$ ./a.out "4444 444k" "4444 444k" - Length 9 - Contains the following duplicate characters : '4' (0x34) at positions : 1 2 3 4 6 7 8
Factor
<lang factor>USING: formatting fry generalizations io kernel math.parser sequences sets ;
- repeated ( elt seq -- )
[ dup >hex over ] dip indices first2 " '%c' (0x%s) at indices %d and %d.\n" printf ;
- uniqueness-report ( str -- )
dup dup length "%u — length %d — contains " printf [ duplicates ] keep over empty? [ 2drop "all unique characters." print ] [ "repeated characters:" print '[ _ repeated ] each ] if ;
"" "." "abcABC" "XYZ ZYX" "1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ" [ uniqueness-report nl ] 5 napply</lang>
- Output:
"" — length 0 — contains all unique characters. "." — length 1 — contains all unique characters. "abcABC" — length 6 — contains all unique characters. "XYZ ZYX" — length 7 — contains repeated characters: 'Z' (0x5a) at indices 2 and 4. 'Y' (0x59) at indices 1 and 5. 'X' (0x58) at indices 0 and 6. "1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ" — length 36 — contains repeated characters: '0' (0x30) at indices 9 and 24.
Go
<lang go>package main
import "fmt"
func analyze(s string) {
chars := []rune(s)
le := len(chars)
fmt.Printf("Analyzing %q which has a length of %d:\n", s, le)
if le > 1 {
for i := 0; i < le-1; i++ {
for j := i + 1; j < le; j++ {
if chars[j] == chars[i] {
fmt.Println(" Not all characters in the string are unique.")
fmt.Printf(" %q (%#[1]x) is duplicated at positions %d and %d.\n\n", chars[i], i+1, j+1)
return
}
}
}
}
fmt.Println(" All characters in the string are unique.\n")
}
func main() {
strings := []string{
"",
".",
"abcABC",
"XYZ ZYX",
"1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ",
"01234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ0X",
"hétérogénéité",
"🎆🎃🎇🎈",
"😍😀🙌💃😍🙌",
"🐠🐟🐡🦈🐬🐳🐋🐡",
}
for _, s := range strings {
analyze(s)
}
}</lang>
- Output:
Analyzing "" which has a length of 0: All characters in the string are unique. Analyzing "." which has a length of 1: All characters in the string are unique. Analyzing "abcABC" which has a length of 6: All characters in the string are unique. Analyzing "XYZ ZYX" which has a length of 7: Not all characters in the string are unique. 'X' (0x58) is duplicated at positions 1 and 7. Analyzing "1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ" which has a length of 36: Not all characters in the string are unique. '0' (0x30) is duplicated at positions 10 and 25. Analyzing "01234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ0X" which has a length of 39: Not all characters in the string are unique. '0' (0x30) is duplicated at positions 1 and 11. Analyzing "hétérogénéité" which has a length of 13: Not all characters in the string are unique. 'é' (0xe9) is duplicated at positions 2 and 4. Analyzing "🎆🎃🎇🎈" which has a length of 4: All characters in the string are unique. Analyzing "😍😀🙌💃😍🙌" which has a length of 6: Not all characters in the string are unique. '😍' (0x1f60d) is duplicated at positions 1 and 5. Analyzing "🐠🐟🐡🦈🐬🐳🐋🐡" which has a length of 8: Not all characters in the string are unique. '🐡' (0x1f421) is duplicated at positions 3 and 8.
Haskell
<lang Haskell>import Data.List (groupBy, intersperse, sort, transpose) import Data.Char (ord, toUpper) import Numeric (showHex)
hexFromChar :: Char -> String hexFromChar c = map toUpper $ showHex (ord c) ""
string :: String -> String string xs = ('\"' : xs) ++ "\""
char :: Char -> String char c = ['\, c, '\]
size :: String -> String size = show . length
positions :: (Int, Int) -> String positions (a, b) = show a ++ " " ++ show b
forTable :: String -> [String] forTable xs = string xs : go (allUnique xs)
where go Nothing = [size xs, "yes", "", "", ""] go (Just (u, ij)) = [size xs, "no", char u, hexFromChar u, positions ij]
showTable :: Bool -> Char -> Char -> Char -> String -> String showTable _ _ _ _ [] = [] showTable header ver hor sep contents =
unlines $
hr :
(if header
then z : hr : zs
else intersperse hr zss) ++
[hr]
where
vss = map (map length) contents
ms = map maximum (transpose vss) :: [Int]
hr = concatMap (\n -> sep : replicate n hor) ms ++ [sep]
top = replicate (length hr) hor
bss = map (map (`replicate` ' ') . zipWith (-) ms) vss
zss@(z:zs) =
zipWith
(\us bs -> concat (zipWith (\x y -> (ver : x) ++ y) us bs) ++ [ver])
contents
bss
table xs =
showTable
True
'|'
'-'
'+'
(["string", "length", "all unique", "1st diff", "hex", "positions"] :
map forTable xs)
allUnique
:: (Ord b, Ord a, Num b, Enum b) => [a] -> Maybe (a, (b, b))
allUnique xs = go . groupBy (\(x, _) (y, _) -> x == y) . sort . zip xs $ [0 ..]
where go [] = Nothing go ([_]:us) = go us go (((u, i):(_, j):_):_) = Just (u, (i, j))
main :: IO () main =
putStrLn $ table ["", ".", "abcABC", "XYZ ZYX", "1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ"]</lang>
- Output:
+--------------------------------------+------+----------+--------+---+---------+ |string |length|all unique|1st diff|hex|positions| +--------------------------------------+------+----------+--------+---+---------+ |"" |0 |yes | | | | |"." |1 |yes | | | | |"abcABC" |6 |yes | | | | |"XYZ ZYX" |7 |no |'X' |58 |0 6 | |"1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ"|36 |no |'0' |30 |9 24 | +--------------------------------------+------+----------+--------+---+---------+
Alternatively, defining a duplicatedCharIndices function in terms of sortOn, groupBy, and filter:
<lang haskell>import Data.List (groupBy, intercalate, sortOn) import Control.Arrow ((&&&)) import Data.Function (on) import Numeric (showHex) import Data.Char (ord)
duplicatedCharIndices :: String -> Maybe (Char, [Int]) duplicatedCharIndices s
| null duplicates = Nothing
| otherwise =
Just $ ((snd . head) &&& fmap fst) (head (sortOn (fst . head) duplicates))
where
duplicates =
filter ((1 <) . length) $
groupBy (on (==) snd) $ sortOn snd $ zip [0 ..] s
TEST----------------------------
main :: IO () main =
putStrLn $
fTable
"First duplicated character, if any:"
((++) <$> show <*> ((" (" ++) . (++ ")") . show . length))
(maybe
"None"
(\(c, ixs) ->
unwords
[ show c
, "(0x" ++ showHex (ord c) ") at"
, intercalate ", " (show <$> ixs)
]))
duplicatedCharIndices
["", ".", "abcABC", "XYZ ZYX", "1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ"]
DISPLAY--------------------------
fTable :: String -> (a -> String) -> (b -> String) -> (a -> b) -> [a] -> String fTable s xShow fxShow f xs =
let rjust n c = drop . length <*> (replicate n c ++)
w = maximum (length . xShow <$> xs)
in unlines $
s : fmap (((++) . rjust w ' ' . xShow) <*> ((" -> " ++) . fxShow . f)) xs</lang>
- Output:
First duplicated character, if any:
"" (0) -> None
"." (1) -> None
"abcABC" (6) -> None
"XYZ ZYX" (7) -> 'X' (0x58) at 0, 6
"1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ" (36) -> '0' (0x30) at 9, 24
Or, as an alternative to grouping and sorting – folding a string down to a Map of indices:
<lang haskell>import qualified Safe as S
import qualified Data.Map.Strict as M
import Data.List (intercalate, foldl') --'
import Data.Ord (comparing)
import Numeric (showHex)
import Data.Char (ord)
duplicatedCharIndices :: String -> Maybe (Char, [Int]) duplicatedCharIndices xs =
S.minimumByMay
(comparing (head . snd))
(M.toList
(M.filter
((1 <) . length)
(foldl' --'
(\a (i, c) -> M.insert c (maybe [i] (++ [i]) (M.lookup c a)) a)
M.empty
(zip [0 ..] xs))))
-- OR, fusing filter, toList, and minimumByMay down to a single fold: duplicatedCharIndices_ :: String -> Maybe (Char, [Int]) duplicatedCharIndices_ xs =
M.foldrWithKey
go
Nothing
(foldl' --'
(\a (i, c) -> M.insert c (maybe [i] (++ [i]) (M.lookup c a)) a)
M.empty
(zip [0 ..] xs))
where
go k [_] mb = mb -- Unique
go k xs Nothing = Just (k, xs) -- Duplicated
go k xs@(x:_) (Just (c, ys@(y:_)))
| x < y = Just (k, xs) -- Earlier duplication
| otherwise = Just (c, ys)
TEST----------------------------
main :: IO () main =
putStrLn $
fTable
"First duplicated character, if any:"
((++) <$> show <*> ((" (" ++) . (++ ")") . show . length))
(maybe
"None"
(\(c, ixs) ->
unwords
[ show c
, "(0x" ++ showHex (ord c) ") at"
, intercalate ", " (show <$> ixs)
]))
duplicatedCharIndices_
["", ".", "abcABC", "XYZ ZYX", "1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ"]
DISPLAY--------------------------
fTable :: String -> (a -> String) -> (b -> String) -> (a -> b) -> [a] -> String fTable s xShow fxShow f xs =
unlines $
s : fmap (((++) . rjust w ' ' . xShow) <*> ((" -> " ++) . fxShow . f)) xs
where
rjust n c = drop . length <*> (replicate n c ++)
w = maximum (length . xShow <$> xs)</lang>
- Output:
First duplicated character, if any:
"" (0) -> None
"." (1) -> None
"abcABC" (6) -> None
"XYZ ZYX" (7) -> 'X' (0x58) at 0, 6
"1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ" (36) -> '0' (0x30) at 9, 24
JavaScript
<lang javascript>(() => {
'use strict';
// duplicatedCharIndices :: String -> Maybe (Char, [Int])
const duplicatedCharIndices = s => {
const
duplicates = filter(g => 1 < g.length)(
groupBy(on(eq)(snd))(
sortOn(snd)(
zip(enumFrom(0))(chars(s))
)
)
);
return 0 < duplicates.length ? Just(
fanArrow(compose(snd, fst))(map(fst))(
sortOn(compose(fst, fst))(
duplicates
)[0]
)
) : Nothing();
};
// ------------------------TEST------------------------
const main = () =>
console.log(
fTable('First duplicated character, if any:')(
s => `'${s}' (${s.length})`
)(maybe('None')(tpl => {
const [c, ixs] = Array.from(tpl);
return `'${c}' (0x${showHex(ord(c))}) at ${ixs.join(', ')}`
}))(duplicatedCharIndices)([
"", ".", "abcABC", "XYZ ZYX",
"1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ"
])
);
// -----------------GENERIC FUNCTIONS------------------
// Just :: a -> Maybe a
const Just = x => ({
type: 'Maybe',
Nothing: false,
Just: x
});
// Nothing :: Maybe a
const Nothing = () => ({
type: 'Maybe',
Nothing: true,
});
// Tuple (,) :: a -> b -> (a, b)
const Tuple = a => b => ({
type: 'Tuple',
'0': a,
'1': b,
length: 2
});
// chars :: String -> [Char] const chars = s => s.split();
// compose (<<<) :: (b -> c) -> (a -> b) -> a -> c
const compose = (...fs) =>
x => fs.reduceRight((a, f) => f(a), x);
// enumFrom :: Enum a => a -> [a]
function* enumFrom(x) {
let v = x;
while (true) {
yield v;
v = 1 + v;
}
}
// eq (==) :: Eq a => a -> a -> Bool const eq = a => b => a === b;
// fanArrow (&&&) :: (a -> b) -> (a -> c) -> (a -> (b, c))
const fanArrow = f =>
// Compose a function from a simple value to a tuple of
// the separate outputs of two different functions.
g => x => Tuple(f(x))(g(x));
// filter :: (a -> Bool) -> [a] -> [a] const filter = f => xs => xs.filter(f);
// fst :: (a, b) -> a const fst = tpl => tpl[0];
// fTable :: String -> (a -> String) -> (b -> String)
// -> (a -> b) -> [a] -> String
const fTable = s => xShow => fxShow => f => xs => {
// Heading -> x display function ->
// fx display function ->
// f -> values -> tabular string
const
ys = xs.map(xShow),
w = Math.max(...ys.map(length));
return s + '\n' + zipWith(
a => b => a.padStart(w, ' ') + ' -> ' + b
)(ys)(
xs.map(x => fxShow(f(x)))
).join('\n');
};
// groupBy :: (a -> a -> Bool) -> [a] -> a const groupBy = fEq => // Typical usage: groupBy(on(eq)(f), xs) xs => 0 < xs.length ? (() => { const tpl = xs.slice(1).reduce( (gw, x) => { const gps = gw[0], wkg = gw[1]; return fEq(wkg[0])(x) ? ( Tuple(gps)(wkg.concat([x])) ) : Tuple(gps.concat([wkg]))([x]); }, Tuple([])([xs[0]]) ); return tpl[0].concat([tpl[1]]) })() : [];
// length :: [a] -> Int
const length = xs =>
// Returns Infinity over objects without finite length.
// This enables zip and zipWith to choose the shorter
// argument when one is non-finite, like cycle, repeat etc
(Array.isArray(xs) || 'string' === typeof xs) ? (
xs.length
) : Infinity;
// map :: (a -> b) -> [a] -> [b]
const map = f => xs =>
(Array.isArray(xs) ? (
xs
) : xs.split()).map(f);
// maybe :: b -> (a -> b) -> Maybe a -> b
const maybe = v =>
// Default value (v) if m is Nothing, or f(m.Just)
f => m => m.Nothing ? v : f(m.Just);
// on :: (b -> b -> c) -> (a -> b) -> a -> a -> c
const on = f =>
g => a => b => f(g(a))(g(b));
// ord :: Char -> Int const ord = c => c.codePointAt(0);
// showHex :: Int -> String
const showHex = n =>
n.toString(16);
// snd :: (a, b) -> b const snd = tpl => tpl[1];
// sortOn :: Ord b => (a -> b) -> [a] -> [a]
const sortOn = f =>
// Equivalent to sortBy(comparing(f)), but with f(x)
// evaluated only once for each x in xs.
// ('Schwartzian' decorate-sort-undecorate).
xs => xs.map(
x => [f(x), x]
).sort(
(a, b) => a[0] < b[0] ? -1 : (a[0] > b[0] ? 1 : 0)
).map(x => x[1]);
// take :: Int -> [a] -> [a]
// take :: Int -> String -> String
const take = n => xs =>
'GeneratorFunction' !== xs.constructor.constructor.name ? (
xs.slice(0, n)
) : [].concat.apply([], Array.from({
length: n
}, () => {
const x = xs.next();
return x.done ? [] : [x.value];
}));
// uncurry :: (a -> b -> c) -> ((a, b) -> c)
const uncurry = f =>
(x, y) => f(x)(y)
// zip :: [a] -> [b] -> [(a, b)]
const zip = xs => ys => {
const
lng = Math.min(length(xs), length(ys)),
vs = take(lng)(ys);
return take(lng)(xs)
.map((x, i) => Tuple(x)(vs[i]));
};
// zipWith :: (a -> b -> c) -> [a] -> [b] -> [c]
const zipWith = f =>
xs => ys => {
const
lng = Math.min(length(xs), length(ys)),
vs = take(lng)(ys);
return take(lng)(xs)
.map((x, i) => f(x)(vs[i]));
};
// MAIN --- return main();
})();</lang>
- Output:
First duplicated character, if any:
'' (0) -> None
'.' (1) -> None
'abcABC' (6) -> None
'XYZ ZYX' (7) -> 'X' (0x58) at 0, 6
'1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ' (36) -> '0' (0x30) at 9, 24
Or, as an alternative to sorting and grouping – folding a string down to a dictionary of indices:
<lang javascript>(() => {
'use strict';
// duplicatedCharIndices :: String -> Maybe (Char, [Int])
const duplicatedCharIndices = s =>
minimumByMay(
comparing(compose(fst, snd))
)(filter(x => 1 < x[1].length)(
Object.entries(
s.split().reduce(
(a, c, i) => Object.assign(a, {
[c]: (a[c] || []).concat(i)
}), {}
)
)
));
// ------------------------TEST------------------------
const main = () =>
console.log(
fTable('First duplicated character, if any:')(
s => `'${s}' (${s.length })`
)(maybe('None')(tpl => {
const [c, ixs] = Array.from(tpl);
return `'${c}' (0x${showHex(ord(c))}) at ${ixs.join(', ')}`
}))(duplicatedCharIndices)([
"", ".", "abcABC", "XYZ ZYX",
"1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ"
])
);
// -----------------GENERIC FUNCTIONS------------------
// Just :: a -> Maybe a
const Just = x => ({
type: 'Maybe',
Nothing: false,
Just: x
});
// Nothing :: Maybe a
const Nothing = () => ({
type: 'Maybe',
Nothing: true,
});
// Tuple (,) :: a -> b -> (a, b)
const Tuple = a => b => ({
type: 'Tuple',
'0': a,
'1': b,
length: 2
});
// chars :: String -> [Char] const chars = s => s.split();
// comparing :: (a -> b) -> (a -> a -> Ordering)
const comparing = f =>
x => y => {
const
a = f(x),
b = f(y);
return a < b ? -1 : (a > b ? 1 : 0);
};
// compose (<<<) :: (b -> c) -> (a -> b) -> a -> c
const compose = (...fs) =>
x => fs.reduceRight((a, f) => f(a), x);
// enumFrom :: Enum a => a -> [a]
function* enumFrom(x) {
let v = x;
while (true) {
yield v;
v = 1 + v;
}
}
// filter :: (a -> Bool) -> [a] -> [a] const filter = f => xs => xs.filter(f);
// fst :: (a, b) -> a const fst = tpl => tpl[0];
// fTable :: String -> (a -> String) -> (b -> String)
// -> (a -> b) -> [a] -> String
const fTable = s => xShow => fxShow => f => xs => {
// Heading -> x display function ->
// fx display function ->
// f -> values -> tabular string
const
ys = xs.map(xShow),
w = Math.max(...ys.map(length));
return s + '\n' + zipWith(
a => b => a.padStart(w, ' ') + ' -> ' + b
)(ys)(
xs.map(x => fxShow(f(x)))
).join('\n');
};
// length :: [a] -> Int
const length = xs =>
// Returns Infinity over objects without finite length.
// This enables zip and zipWith to choose the shorter
// argument when one is non-finite, like cycle, repeat etc
(Array.isArray(xs) || 'string' === typeof xs) ? (
xs.length
) : Infinity;
// maybe :: b -> (a -> b) -> Maybe a -> b
const maybe = v =>
// Default value (v) if m is Nothing, or f(m.Just)
f => m => m.Nothing ? v : f(m.Just);
// minimumByMay :: (a -> a -> Ordering) -> [a] -> Maybe a
const minimumByMay = f =>
xs => xs.reduce((a, x) =>
a.Nothing ? Just(x) : (
f(x)(a.Just) < 0 ? Just(x) : a
), Nothing());
// ord :: Char -> Int const ord = c => c.codePointAt(0);
// showHex :: Int -> String
const showHex = n =>
n.toString(16);
// snd :: (a, b) -> b
const snd = tpl =>
tpl[1];
// take :: Int -> [a] -> [a]
// take :: Int -> String -> String
const take = n =>
xs => 'GeneratorFunction' !== xs.constructor.constructor.name ? (
xs.slice(0, n)
) : [].concat.apply([], Array.from({
length: n
}, () => {
const x = xs.next();
return x.done ? [] : [x.value];
}));
// zipWith :: (a -> b -> c) -> [a] -> [b] -> [c]
const zipWith = f =>
xs => ys => {
const
lng = Math.min(length(xs), length(ys)),
vs = take(lng)(ys);
return take(lng)(xs)
.map((x, i) => f(x)(vs[i]));
};
// MAIN --- return main();
})();</lang>
- Output:
First duplicated character, if any:
'' (0) -> None
'.' (1) -> None
'abcABC' (6) -> None
'XYZ ZYX' (7) -> 'X' (0x58) at 0, 6
'1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ' (36) -> '0' (0x30) at 9, 24
Julia
<lang julia>arr(s) = [c for c in s] alldup(a) = filter(x -> length(x) > 1, [findall(x -> x == a[i], a) for i in 1:length(a)]) firstduplicate(s) = (a = arr(s); d = alldup(a); isempty(d) ? nothing : first(d))
function testfunction(strings)
println("String | Length | All Unique | First Duplicate | Positions\n" *
"-------------------------------------------------------------------------------------")
for s in strings
n = firstduplicate(s)
a = arr(s)
println(rpad(s, 38), rpad(length(s), 11), n == nothing ? "yes" :
rpad("no $(a[n[1]])", 26) * rpad(n[1], 4) * "$(n[2])")
end
end
testfunction([ "", ".", "abcABC", "XYZ ZYX", "1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ",
"hétérogénéité",
"🎆🎃🎇🎈", "😍😀🙌💃😍🙌", "🐠🐟🐡🦈🐬🐳🐋🐡", ])
</lang>
- Output:
String | Length | All Unique | First Duplicate (Hex) | Positions
-------------------------------------------------------------------------------------------
0 yes
. 1 yes
abcABC 6 yes
XYZ ZYX 7 no X (58) 1 7
1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ 36 no 0 (30) 10 25
hétérogénéité 13 no é (e9) 2 4
🎆🎃🎇🎈 4 yes
😍😀🙌💃😍🙌 6 no 😍 (1f60d) 1 5
🐠🐟🐡🦈🐬🐳🐋🐡 8 no 🐡 (1f421) 3 8
Perl
<lang perl>use strict; use warnings; use feature 'say'; use utf8; binmode(STDOUT, ':utf8'); use List::AllUtils qw(uniq); use Unicode::UCD 'charinfo';
for my $str (
, '.', 'abcABC', 'XYZ ZYX', '1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ', '01234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ0X', 'Δ👍👨👍Δ', 'ΔδΔ̂ΔΛ',
) {
my @S;
push @S, $1 while $str =~ /(\X)/g;
printf qq{\n"$str" (length: %d) has }, scalar @S;
if (@S != uniq @S ) {
say "duplicated characters:";
my %P;
push @{ $P{$S[$_]} }, 1+$_ for 0..$#S;
for my $k (sort keys %P) {
next unless @{$P{$k}} > 1;
printf "'%s' %s (0x%x) in positions: %s\n", $k, charinfo(ord $k)->{'name'}, ord($k), join ', ', @{$P{$k}};
}
} else {
say "no duplicated characters."
}
}</lang>
- Output:
"" (length: 0) has no duplicated characters. "." (length: 1) has no duplicated characters. "abcABC" (length: 6) has no duplicated characters. "XYZ ZYX" (length: 7) has duplicated characters: 'X' LATIN CAPITAL LETTER X (0x58) in positions: 1, 7 'Y' LATIN CAPITAL LETTER Y (0x59) in positions: 2, 6 'Z' LATIN CAPITAL LETTER Z (0x5a) in positions: 3, 5 "1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ" (length: 36) has duplicated characters: '0' DIGIT ZERO (0x30) in positions: 10, 25 "01234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ0X" (length: 39) has duplicated characters: '0' DIGIT ZERO (0x30) in positions: 1, 11, 26, 38 'X' LATIN CAPITAL LETTER X (0x58) in positions: 35, 39 "Δ👍👨👍Δ" (length: 5) has duplicated characters: 'Δ' GREEK CAPITAL LETTER DELTA (0x394) in positions: 1, 5 '👍' THUMBS UP SIGN (0x1f44d) in positions: 2, 4 "ΔδΔ̂ΔΛ" (length: 5) has duplicated characters: 'Δ' GREEK CAPITAL LETTER DELTA (0x394) in positions: 1, 4
Perl 6
Perl 6 works with unicode natively and handles combining characters and multi-byte emoji correctly. In the last string, notice the the length is correctly shown as 11 characters and that the delta with a combining circumflex in position 6 is not the same as the deltas without in positions 5 & 9.
<lang perl6> -> $str {
my $i = 0;
print "\n{$str.perl} (length: {$str.chars}), has ";
my %m;
%m{$_}.push: ++$i for $str.comb;
if any(%m.values) > 1 {
say "duplicated characters:";
say "'{.key}' ({.key.uninames}; hex ordinal: {(.key.ords).fmt: "0x%X"})" ~
" in positions: {.value.join: ', '}" for %m.grep( *.value > 1 ).sort( *.value[0] );
} else {
say "no duplicated characters."
}
} for
, '.', 'abcABC', 'XYZ ZYX', '1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ', '01234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ0X', '🦋🙂👨👩👧👦🙄ΔΔ̂ 🦋Δ👍👨👩👧👦'</lang>
- Output:
"" (length: 0), has no duplicated characters. "." (length: 1), has no duplicated characters. "abcABC" (length: 6), has no duplicated characters. "XYZ ZYX" (length: 7), has duplicated characters: 'X' (LATIN CAPITAL LETTER X; hex ordinal: 0x58) in positions: 1, 7 'Y' (LATIN CAPITAL LETTER Y; hex ordinal: 0x59) in positions: 2, 6 'Z' (LATIN CAPITAL LETTER Z; hex ordinal: 0x5A) in positions: 3, 5 "1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ" (length: 36), has duplicated characters: '0' (DIGIT ZERO; hex ordinal: 0x30) in positions: 10, 25 "01234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ0X" (length: 39), has duplicated characters: '0' (DIGIT ZERO; hex ordinal: 0x30) in positions: 1, 11, 26, 38 'X' (LATIN CAPITAL LETTER X; hex ordinal: 0x58) in positions: 35, 39 "🦋🙂👨👩👧👦🙄ΔΔ̂ 🦋Δ👍👨👩👧👦" (length: 11), has duplicated characters: '🦋' (BUTTERFLY; hex ordinal: 0x1F98B) in positions: 1, 8 '👨👩👧👦' (MAN ZERO WIDTH JOINER WOMAN ZERO WIDTH JOINER GIRL ZERO WIDTH JOINER BOY; hex ordinal: 0x1F468 0x200D 0x1F469 0x200D 0x1F467 0x200D 0x1F466) in positions: 3, 11 'Δ' (GREEK CAPITAL LETTER DELTA; hex ordinal: 0x394) in positions: 5, 9
Phix
As with Determine_if_a_string_has_all_the_same_characters#Phix, you can use utf8_to_utf32() when needed. <lang Phix>procedure all_uniq(sequence s)
string msg = "all characters are unique"
for i=1 to length(s) do
integer si = s[i],
r = find(si,s,i+1) -- (or maybe rfind(si,s,i-1))
if r then
msg = sprintf(`first duplicate character "%c"(#%02x) at positions %d and %d`,{si,si,i,r})
exit
end if
end for
printf(1,"\"%s\" (length %d): %s\n",{s,length(s),msg})
end procedure
constant tests = {"",".","abcABC","XYZ ZYX","1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ"} for i=1 to length(tests) do all_uniq(tests[i]) end for</lang>
- Output:
"" (length 0): all characters are unique "." (length 1): all characters are unique "abcABC" (length 6): all characters are unique "XYZ ZYX" (length 7): first duplicate character "X"(#58) at positions 1 and 7 "1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ" (length 36): first duplicate character "0"(#30) at positions 10 and 25
Python
Functional
Defined in terms of itertools.groupby:
<lang python>Determine if a string has all unique characters
from itertools import groupby
- duplicatedCharIndices :: String -> Maybe (Char, [Int])
def duplicatedCharIndices(s):
Just the first duplicated character, and
the indices of its occurrence, or
Nothing if there are no duplications.
def go(xs):
if 1 < len(xs):
duplicates = list(filter(lambda kv: 1 < len(kv[1]), [
(k, list(v)) for k, v in groupby(
sorted(xs, key=swap),
key=snd
)
]))
return Just(second(fmap(fst))(
sorted(
duplicates,
key=lambda kv: kv[1][0]
)[0]
)) if duplicates else Nothing()
else:
return Nothing()
return go(list(enumerate(s)))
- TEST ----------------------------------------------------
- main :: IO ()
def main():
Test over various strings.
def showSample(s):
return repr(s) + ' (' + str(len(s)) + ')'
def showDuplicate(cix):
c, ix = cix
return repr(c) + (
' (' + hex(ord(c)) + ') at ' + repr(ix)
)
print(
fTable('First duplicated character, if any:')(
showSample
)(maybe('None')(showDuplicate))(duplicatedCharIndices)([
, '.', 'abcABC', 'XYZ ZYX',
'1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ'
])
)
- FORMATTING ----------------------------------------------
- fTable :: String -> (a -> String) ->
- (b -> String) -> (a -> b) -> [a] -> String
def fTable(s):
Heading -> x display function -> fx display function ->
f -> xs -> tabular string.
def go(xShow, fxShow, f, xs):
ys = [xShow(x) for x in xs]
w = max(map(len, ys))
return s + '\n' + '\n'.join(map(
lambda x, y: y.rjust(w, ' ') + ' -> ' + fxShow(f(x)),
xs, ys
))
return lambda xShow: lambda fxShow: lambda f: lambda xs: go(
xShow, fxShow, f, xs
)
- GENERIC -------------------------------------------------
- Just :: a -> Maybe a
def Just(x):
Constructor for an inhabited Maybe (option type) value.
Wrapper containing the result of a computation.
return {'type': 'Maybe', 'Nothing': False, 'Just': x}
- Nothing :: Maybe a
def Nothing():
Constructor for an empty Maybe (option type) value.
Empty wrapper returned where a computation is not possible.
return {'type': 'Maybe', 'Nothing': True}
- fmap :: (a -> b) -> [a] -> [b]
def fmap(f):
fmap over a list.
f lifted to a function over a list.
return lambda xs: [f(x) for x in xs]
- fst :: (a, b) -> a
def fst(tpl):
First member of a pair. return tpl[0]
- head :: [a] -> a
def head(xs):
The first element of a non-empty list. return xs[0] if isinstance(xs, list) else next(xs)
- maybe :: b -> (a -> b) -> Maybe a -> b
def maybe(v):
Either the default value v, if m is Nothing,
or the application of f to x,
where m is Just(x).
return lambda f: lambda m: v if (
None is m or m.get('Nothing')
) else f(m.get('Just'))
- second :: (a -> b) -> ((c, a) -> (c, b))
def second(f):
A simple function lifted to a function over a tuple,
with f applied only to the second of two values.
return lambda xy: (xy[0], f(xy[1]))
- snd :: (a, b) -> b
def snd(tpl):
Second member of a pair. return tpl[1]
- swap :: (a, b) -> (b, a)
def swap(tpl):
The swapped components of a pair. return (tpl[1], tpl[0])
- MAIN ---
if __name__ == '__main__':
main()</lang>
- Output:
First duplicated character, if any:
'' (0) -> None
'.' (1) -> None
'abcABC' (6) -> None
'XYZ ZYX' (7) -> 'X' (0x58) at [0, 6]
'1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ' (36) -> '0' (0x30) at [9, 24]
Or, as an alternative to sorting and grouping, folding a string down to a dictionary with reduce:
<lang python>Determine if a string has all unique characters
from functools import reduce
- duplicatedCharIndices :: String -> Maybe (Char, [Int])
def duplicatedCharIndices(s):
Just the first duplicated character, and
the indices of its occurrence, or
Nothing if there are no duplications.
def go(dct, ic):
i, c = ic
return dict(
dct,
**{c: dct[c] + [i] if c in dct else [i]}
)
duplicates = [
(k, v) for (k, v)
in reduce(go, enumerate(s), {}).items()
if 1 < len(v)
]
return Just(
min(duplicates, key=compose(head, snd))
) if duplicates else Nothing()
- And another alternative here would be to fuse the 1 < len(v)
- filtering, and the min() search for the earliest duplicate,
- down to a single `earliestDuplication` fold:
- duplicatedCharIndices_ :: String -> Maybe (Char, [Int])
def duplicatedCharIndices_(s):
Just the first duplicated character, and
the indices of its occurrence, or
Nothing if there are no duplications.
def positionRecord(dct, ic):
i, c = ic
return dict(
dct,
**{c: dct[c] + [i] if c in dct else [i]}
)
def earliestDuplication(sofar, charPosns):
c, indices = charPosns
return (
Just((c, indices)) if sofar['Nothing'] else (
# Earlier ?
Just((c, indices)) if (
indices[0] < sofar['Just'][1][0]
) else sofar
)
) if 1 < len(indices) else sofar
return reduce(
earliestDuplication,
reduce(
positionRecord,
enumerate(s), {}
).items(),
Nothing()
)
- TEST ----------------------------------------------------
- main :: IO ()
def main():
Test over various strings.
def showSample(s):
return repr(s) + ' (' + str(len(s)) + ')'
def showDuplicate(cix):
c, ix = cix
return repr(c) + (
' (' + hex(ord(c)) + ') at ' + repr(ix)
)
print(
fTable('First duplicated character, if any:')(
showSample
)(maybe('None')(showDuplicate))(duplicatedCharIndices_)([
, '.', 'abcABC', 'XYZ ZYX',
'1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ'
])
)
- FORMATTING ----------------------------------------------
- fTable :: String -> (a -> String) ->
- (b -> String) -> (a -> b) -> [a] -> String
def fTable(s):
Heading -> x display function -> fx display function ->
f -> xs -> tabular string.
def go(xShow, fxShow, f, xs):
ys = [xShow(x) for x in xs]
w = max(map(len, ys))
return s + '\n' + '\n'.join(map(
lambda x, y: y.rjust(w, ' ') + ' -> ' + fxShow(f(x)),
xs, ys
))
return lambda xShow: lambda fxShow: lambda f: lambda xs: go(
xShow, fxShow, f, xs
)
- GENERIC -------------------------------------------------
- Just :: a -> Maybe a
def Just(x):
Constructor for an inhabited Maybe (option type) value.
Wrapper containing the result of a computation.
return {'type': 'Maybe', 'Nothing': False, 'Just': x}
- Nothing :: Maybe a
def Nothing():
Constructor for an empty Maybe (option type) value.
Empty wrapper returned where a computation is not possible.
return {'type': 'Maybe', 'Nothing': True}
- compose :: ((a -> a), ...) -> (a -> a)
def compose(*fs):
Composition, from right to left,
of a series of functions.
return lambda x: reduce(
lambda a, f: f(a),
fs[::-1], x
)
- head :: [a] -> a
def head(xs):
The first element of a non-empty list. return xs[0] if isinstance(xs, list) else next(xs)
- maybe :: b -> (a -> b) -> Maybe a -> b
def maybe(v):
Either the default value v, if m is Nothing,
or the application of f to x,
where m is Just(x).
return lambda f: lambda m: v if (
None is m or m.get('Nothing')
) else f(m.get('Just'))
- snd :: (a, b) -> b
def snd(tpl):
Second member of a pair. return tpl[1]
- MAIN ---
if __name__ == '__main__':
main()</lang>
- Output:
First duplicated character, if any:
'' (0) -> None
'.' (1) -> None
'abcABC' (6) -> None
'XYZ ZYX' (7) -> 'X' (0x58) at [0, 6]
'1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ' (36) -> '0' (0x30) at [9, 24]
REXX
<lang rexx>/*REXX pgm determines if a string is comprised of all unique characters (no duplicates).*/ @.= /*assign a default for the @. array. */ parse arg @.1 /*obtain optional argument from the CL.*/ if @.1= then do; @.1= /*Not specified? Then assume defaults.*/
@.2= .
@.3= 'abcABC'
@.4= 'XYZ ZYX'
@.5= '1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ'
end
do j=1; if j\==1 & @.j== then leave /*String is null & not j=1? We're done*/
say copies('─', 79) /*display a separator line (a fence). */
say 'Testing for the string (length' length(@.j)"): " @.j
say
dup= isUnique(@.j)
say 'The characters in the string' word("are aren't", 1 + (dup>0) ) 'all unique.'
if dup==0 then iterate
?= substr(@.j, dup, 1)
say 'The character ' ? " ('"c2x(?)"'x) at position " dup ,
' is repeated at position ' pos(?, @.j, dup+1)
end /*j*/
exit /*stick a fork in it, we're all done. */ /*──────────────────────────────────────────────────────────────────────────────────────*/ isUnique: procedure; parse arg x /*obtain the character string.*/
do k=1 to length(x) - 1 /*examine all but the last. */
p= pos( substr(x, k, 1), x, k + 1) /*see if the Kth char is a dup*/
if p\==0 then return k /*Find a dup? Return location.*/
end /*k*/
return 0 /*indicate all chars unique. */</lang>
- output when using the internal defaults
───────────────────────────────────────────────────────────────────────────────
Testing for the string (length 0):
The characters in the string are all unique.
───────────────────────────────────────────────────────────────────────────────
Testing for the string (length 1): .
The characters in the string are all unique.
───────────────────────────────────────────────────────────────────────────────
Testing for the string (length 6): abcABC
The characters in the string are all unique.
───────────────────────────────────────────────────────────────────────────────
Testing for the string (length 7): XYZ ZYX
The characters in the string aren't all unique.
The character X ('58'x) at position 1 is repeated at position 7
───────────────────────────────────────────────────────────────────────────────
Testing for the string (length 36): 1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ
The characters in the string aren't all unique.
The character 0 ('30'x) at position 10 is repeated at position 25
Ruby
<lang ruby>strings = ["",
".",
"abcABC",
"XYZ ZYX",
"1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ",
"01234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ0X",
"hétérogénéité",
"🎆🎃🎇🎈",
"😍😀🙌💃😍🙌",
"🐠🐟🐡🦈🐬🐳🐋🐡",]
strings.each do |str|
seen = {}
print "#{str.inspect} (size #{str.size}) "
res = "has no duplicates." #may change
str.chars.each_with_index do |c,i|
if seen[c].nil?
seen[c] = i
else
res = "has duplicate char #{c} (#{'%#x' % c.ord}) on #{seen[c]} and #{i}."
break
end
end
puts res
end </lang>
- Output:
"" (size 0) has no duplicates. "." (size 1) has no duplicates. "abcABC" (size 6) has no duplicates. "XYZ ZYX" (size 7) has duplicate char Z (0x5a) on 2 and 4. "1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ" (size 36) has duplicate char 0 (0x30) on 9 and 24. "01234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ0X" (size 39) has duplicate char 0 (0x30) on 0 and 10. "hétérogénéité" (size 13) has duplicate char é (0xe9) on 1 and 3. "🎆🎃🎇🎈" (size 4) has no duplicates. "😍😀🙌💃😍🙌" (size 6) has duplicate char 😍 (0x1f60d) on 0 and 4. "🐠🐟🐡🦈🐬🐳🐋🐡" (size 8) has duplicate char 🐡 (0x1f421) on 2 and 7.
Tcl
<lang tcl>package require Tcl 8.6 ; # For binary encode
array set yesno {1 Yes 2 No}
set test {
{}
{.}
{abcABC}
{XYZ ZYX}
{1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ}
{hétérogénéité}
}
- Loop through test strings
foreach str $test {
set chars [dict create] ; # init dictionary set num_chars 1 ; # In case of empty string
# Loop through characters in string
for {set i 0} {$i < [string length $str]} {incr i} {
set c [string index $str $i] ; # get char at index
dict lappend chars $c $i ; # add index to a running list for key=char
set indexes [dict get $chars $c] ; # get the whole running list
set num_chars [llength $indexes] ; # count the # of indexes
if {$num_chars > 1} {
break ; # Found a duplicate, break out of the loop
}
}
# Handle Output
puts [format "Tested: %38s (len: %2d). All unique? %3s. " \
"'$str'" [string length $str] $yesno($num_chars)]
if {$num_chars > 1} {
puts [format " --> Character '%s' (hex: 0x%s) reappears at indexes: %s." \
$c [binary encode hex $c] $indexes]
}
} </lang>
- Output:
Tested: '' (len: 0). All unique? Yes. Tested: '.' (len: 1). All unique? Yes. Tested: 'abcABC' (len: 6). All unique? Yes. Tested: 'XYZ ZYX' (len: 7). All unique? No. --> Character 'Z' (hex: 0x5a) reappears at indexes: 2 4. Tested: '1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ' (len: 36). All unique? No. --> Character '0' (hex: 0x30) reappears at indexes: 9 24. Tested: 'hétérogénéité' (len: 13). All unique? No. --> Character 'é' (hex: 0xe9) reappears at indexes: 1 3.
XPL0
<lang XPL0>include xpllib; \contains StrLen function
proc StrUnique(S); \Show if string has unique chars char S; int L, I, J, K; [L:= StrLen(S); IntOut(0, L); Text(0, ": ^""); Text(0, S); ChOut(0, ^"); CrLf(0); for I:= 0 to L-1 do
for J:= I+1 to L-1 do
[if S(I) = S(J) then
[ChOut(0, \tab\ 9);
for K:= 0 to I do ChOut(0, ^ );
ChOut(0, ^^);
for K:= 0 to J-I-2 do ChOut(0, ^ );
ChOut(0, ^^);
Text(0, " Duplicate character: ");
ChOut(0, S(I));
Text(0, ", hex ");
SetHexDigits(2);
HexOut(0, S(I));
CrLf(0);
return;
];
];
Text(0, " Unique, no duplicates"); CrLf(0); ];
[Text(0, "Length"); CrLf(0); StrUnique(""); StrUnique("."); StrUnique("abcABC"); StrUnique("XYZ ZYX"); StrUnique("1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ"); StrUnique("thequickbrownfoxjumps"); ]</lang>
- Output:
Length
0: ""
Unique, no duplicates
1: "."
Unique, no duplicates
6: "abcABC"
Unique, no duplicates
7: "XYZ ZYX"
^ ^ Duplicate character: X, hex 58
36: "1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ"
^ ^ Duplicate character: 0, hex 30
21: "thequickbrownfoxjumps"
^ ^ Duplicate character: u, hex 75
zkl
<lang zkl>fcn stringUniqueness(str){ // Does not handle Unicode
sz,unique,uz,counts := str.len(), str.unique(), unique.len(), str.counts();
println("Length %d: \"%s\"".fmt(sz,str));
if(sz==uz or uz==1) println("\tAll characters are unique");
else // counts is (char,count, char,count, ...)
println("\tDuplicate: ",
counts.pump(List,Void.Read,fcn(str,c,n){
if(n>1){
is,z:=List(),-1; do(n){ is.append(z=str.find(c,z+1)) } "'%s' (0x%x)[%s]".fmt(c,c.toAsc(),is.concat(",")) } else Void.Skip }.fp(str)).concat(", ")); }</lang> <lang zkl>testStrings:=T("", ".", "abcABC", "XYZ ZYX",
"1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ", "01234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ0X");
foreach s in (testStrings){ stringUniqueness(s) }</lang>
- Output:
Length 0: "" All characters are unique Length 1: "." All characters are unique Length 6: "abcABC" All characters are unique Length 7: "XYZ ZYX" Duplicate: 'X' (0x58)[0,6], 'Y' (0x59)[1,5], 'Z' (0x5a)[2,4] Length 36: "1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ" Duplicate: '0' (0x30)[9,24] Length 39: "01234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ0X" Duplicate: '0' (0x30)[0,10,25,37], 'X' (0x58)[34,38]