Floyd's triangle

From Rosetta Code
Task
Floyd's triangle
You are encouraged to solve this task according to the task description, using any language you may know.

Floyd's triangle   lists the natural numbers in a right triangle aligned to the left where

  • the first row is   1     (unity)
  • successive rows start towards the left with the next number followed by successive naturals listing one more number than the line above.


The first few lines of a Floyd triangle looks like this:

 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15


Task
  1. Write a program to generate and display here the first   n   lines of a Floyd triangle.
    (Use   n=5   and   n=14   rows).
  2. Ensure that when displayed in a mono-space font, the numbers line up in vertical columns as shown and that only one space separates numbers of the last row.



11l

Translation of: Python

<lang 11l>F floyd(rowcount)

  V rows = 1
  L rows.len < rowcount
     V n = rows.last.last + 1
     rows.append(Array(n .. n + rows.last.len))
  R rows

F pfloyd(rows)

  V colspace = rows.last.map(n -> String(n).len)
  L(row) rows
     print(zip(colspace, row).map2((space, n) -> String(n).rjust(space)).join(‘ ’))

pfloyd(floyd(5)) pfloyd(floyd(14))</lang>

Output:
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35 36
37 38 39 40 41 42 43 44  45
46 47 48 49 50 51 52 53  54  55
56 57 58 59 60 61 62 63  64  65  66
67 68 69 70 71 72 73 74  75  76  77  78
79 80 81 82 83 84 85 86  87  88  89  90  91
92 93 94 95 96 97 98 99 100 101 102 103 104 105

360 Assembly

This example is incorrect. Please fix the code and remove this message.

Details: The last line should only have one space between values

A very concise coding, an illustration of CISC power of the S/360 operation codes. Also an example of the use of EDMK and EX instructions. For macro usage see Structured Macros . <lang 360asm>* Floyd's triangle 21/06/2018 FLOYDTRI PROLOG

        L      R5,NN              nn
        BCTR   R5,0               -1
        M      R4,NN              nn*(nn-1)
        SRA    R5,1               /2
        A      R5,NN              m=(nn*(nn-1))/2+nn; max_value
        CVD    R5,XDEC            binary to packed decimal (PL8)
        EDMK   ZN,XDEC+4          packed dec (PL4) to char (CL8)
        S      R1,=A(ZN)          r1=number of spaces
        L      R9,=A(L'ZN+1)      length(zn08)+1
        SR     R9,R1              s=length(m)+1
        SR     R8,R8              k=0
        LA     R6,1               i=1
      DO WHILE=(C,R6,LE,NN)       do i=1 to nn
        LA     R10,PG               pgi=0
        LA     R7,1                 j=1
      DO WHILE=(CR,R7,LE,R6)          do j=1 to i
        LA     R8,1(R8)               k=k+1
        XDECO  R8,XDEC                k
        LA     R11,XDEC+12            +12
        SR     R11,R9                 -s
        LR     R2,R9                  s
        BCTR   R2,0                   -1
        EX     R2,MVCX                mvc @PG+pgi,@XDEC+12-s,LEN=s
        AR     R10,R9                 pgi+=s
        LA     R7,1(R7)               j++
      ENDDO    ,                    enddo j
        XPRNT  PG,L'PG              print buffer
        LA     R6,1(R6)             i++
      ENDDO    ,                  enddo i
        EPILOG

MVCX MVC 0(0,R10),0(R11) mvc PG,XDEC NN DC F'14' number of rows PG DC CL80' ' buffer XDEC DS CL12 temp ZN DC X'4020202020202020' mask CL8 7num

        YREGS
        END    FLOYDTRI</lang>
Output:
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
Output:
   1
   2   3
   4   5   6
   7   8   9  10
  11  12  13  14  15
  16  17  18  19  20  21
  22  23  24  25  26  27  28
  29  30  31  32  33  34  35  36
  37  38  39  40  41  42  43  44  45
  46  47  48  49  50  51  52  53  54  55
  56  57  58  59  60  61  62  63  64  65  66
  67  68  69  70  71  72  73  74  75  76  77  78
  79  80  81  82  83  84  85  86  87  88  89  90  91
  92  93  94  95  96  97  98  99 100 101 102 103 104 105

Action!

<lang Action!>PROC Triangle(BYTE level)

 INT v,i
 BYTE x,y
 BYTE ARRAY widths(20)
 CHAR ARRAY tmp(5)
 v=1
 FOR y=1 TO level-1
 DO
   v==+y
 OD
 FOR x=0 TO level-1
 DO
   StrI(v+x,tmp)
   widths(x)=tmp(0)
 OD
 v=1
 FOR y=1 TO level
 DO
   FOR x=0 TO y-1
   DO
     StrI(v,tmp)
     FOR i=tmp(0) TO widths(x)-1
     DO 
       Put(32)
     OD
     Print(tmp)
     IF x<y-1 THEN
       Put(32)
     ELSE
       PutE()
     FI
     v==+1
   OD
 OD

RETURN

PROC Main()

 BYTE LMARGIN=$52,oldLMARGIN
 oldLMARGIN=LMARGIN
 LMARGIN=0 ;remove left margin on the screen
 Put(125) PutE() ;clear the screen
 Triangle(5)
 PutE()
 Triangle(13)
 LMARGIN=oldLMARGIN ;restore left margin on the screen

RETURN</lang>

Output:

Screenshot from Atari 8-bit computer

 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15

 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35 36
37 38 39 40 41 42 43 44 45
46 47 48 49 50 51 52 53 54 55
56 57 58 59 60 61 62 63 64 65 66
67 68 69 70 71 72 73 74 75 76 77 78
79 80 81 82 83 84 85 86 87 88 89 90 91

Ada

<lang Ada> with Ada.Text_IO, Ada.Integer_Text_IO, Ada.Command_Line;

procedure Floyd_Triangle is

 rows : constant Natural := Natural'Value(Ada.Command_Line.Argument(1));

begin

 for r in 1..rows loop
   for i in 1..r loop 
     Ada.Integer_Text_IO.put (r*(r-1)/2+i, Width=> Natural'Image(rows*(rows-1)/2+i)'Length); 
   end loop;
   Ada.Text_IO.New_Line;
 end loop;

end Floyd_Triangle; </lang>

Output:
> ./floyd_triangle_triangle 5
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15


> ./floyd_triangle 14
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

ALGOL 68

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

<lang algol68># procedure to print a Floyd's Triangle with n lines # PROC floyds triangle = ( INT n )VOID: BEGIN

   # calculate the number of the highest number that will be printed     #
   # ( the sum of the integers 1, 2, ... n )                             #
   INT max number = ( n * ( n + 1 ) ) OVER 2;
   # determine the widths required to print the numbers of the final row #
   [ n ]INT widths;
   INT number := max number + 1;
   FOR col FROM n BY -1 TO 1 DO
       widths[ col ] := - ( UPB whole( number -:= 1, 0 ) + 1 )
   OD;
   # print the triangle                                                  #
   INT element := 0;
   FOR row TO n DO
       FOR col TO row DO
           print( ( whole( element +:= 1, widths[ col ] ) ) )
       OD;
       print( ( newline ) )
   OD

END; # floyds triangle #

main: (

   floyds triangle(  5 );
   print( ( newline ) );
   floyds triangle( 14 )

)</lang>

Output:
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15

  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

ALGOL W

Translation of: ALgOL_68

<lang algolw>begin

   % prints a Floyd's Triangle with n lines                                  %
   procedure floydsTriangle ( integer value n ) ;
   begin
       % the triangle should be left aligned with the individual numbers     %
       % right-aligned with only one space before the number in the final    %
       % row                                                                 %
       % calculate the highest number that will be printed                   %
       % ( the sum of the integeregers 1, 2, ... n )                         %
       integer array widths( 1 :: n );
       integer maxNumber, number;
       maxNumber := ( n * ( n + 1 ) ) div 2;
       % determine the widths required to print the numbers of the final row %
       number := maxNumber;
       for col := n step -1 until 1 do begin
           integer v, w;
           w      := 0;
           v      := number;
           number := number - 1;
           while v > 0 do begin
               w  := w + 1;
               v  := v div 10
           end while_v_gt_0 ;
           widths( col ) := w
       end for_col;
       % print the triangle                                                  %
       number := 0;
       for row := 1 until n do begin
           for col := 1 until row do begin
               number := number + 1;
               writeon( i_w := widths( col ), s_w := 0, " ", number )
           end for_col ;
           write()
       end for_row 
   end; % floyds triangle %
   floydsTriangle(  5 );
   write();
   floydsTriangle( 14 )

end.</lang>

Output:
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15

  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

AppleScript

Functional

Translation of: JavaScript
Translation of: Haskell

(mapAccumL versions)

<lang AppleScript>-- FLOYDs TRIANGLE -----------------------------------------------------------

-- floyd :: Int -> Int on floyd(n)

   script floydRow
       on |λ|(start, row)
           {start + row + 1, enumFromTo(start, start + row)}
       end |λ|
   end script
   
   snd(mapAccumL(floydRow, 1, enumFromTo(0, n - 1)))

end floyd

-- showFloyd :: Int -> String on showFloyd(xss)

   set ws to map(compose({my succ, my |length|, my show}), |last|(xss))
   
   script aligned
       on |λ|(xs)
           script pad
               on |λ|(w, x)
                   justifyRight(w, space, show(x))
               end |λ|
           end script
           
           concat(zipWith(pad, ws, xs))
       end |λ|
   end script
   
   unlines(map(aligned, xss))

end showFloyd


-- TEST ---------------------------------------------------------------------- on run

   script test
       on |λ|(n)
           showFloyd(floyd(n)) & linefeed
       end |λ|
   end script
   
   unlines(map(test, {5, 14}))

end run


-- GENERIC FUNCTIONS ---------------------------------------------------------

-- compose :: [(a -> a)] -> (a -> a) on compose(fs)

   script
       on |λ|(x)
           script
               on |λ|(f, a)
                   mReturn(f)'s |λ|(a)
               end |λ|
           end script
           
           foldr(result, x, fs)
       end |λ|
   end script

end compose

-- concat :: a -> [a] | [String] -> String on concat(xs)

   if length of xs > 0 and class of (item 1 of xs) is string then
       set acc to ""
   else
       set acc to {}
   end if
   repeat with i from 1 to length of xs
       set acc to acc & item i of xs
   end repeat
   acc

end concat

-- enumFromTo :: Int -> Int -> [Int] on enumFromTo(m, n)

   if n < m then
       set d to -1
   else
       set d to 1
   end if
   set lst to {}
   repeat with i from m to n by d
       set end of lst to i
   end repeat
   return lst

end enumFromTo

-- foldl :: (a -> b -> a) -> a -> [b] -> a on foldl(f, startValue, xs)

   tell mReturn(f)
       set v to startValue
       set lng to length of xs
       repeat with i from 1 to lng
           set v to |λ|(v, item i of xs, i, xs)
       end repeat
       return v
   end tell

end foldl

-- foldr :: (b -> a -> a) -> a -> [b] -> a on foldr(f, startValue, xs)

   tell mReturn(f)
       set v to startValue
       set lng to length of xs
       repeat with i from lng to 1 by -1
           set v to |λ|(item i of xs, v, i, xs)
       end repeat
       return v
   end tell

end foldr

-- intercalate :: Text -> [Text] -> Text on intercalate(strText, lstText)

   set {dlm, my text item delimiters} to {my text item delimiters, strText}
   set strJoined to lstText as text
   set my text item delimiters to dlm
   return strJoined

end intercalate

-- justifyRight :: Int -> Char -> Text -> Text on justifyRight(n, cFiller, strText)

   if n > length of strText then
       text -n thru -1 of ((replicate(n, cFiller) as text) & strText)
   else
       strText
   end if

end justifyRight

-- last :: [a] -> a on |last|(xs)

   if length of xs > 0 then
       item -1 of xs
   else
       missing value
   end if

end |last|

-- length :: [a] -> Int on |length|(xs)

   length of xs

end |length|

-- map :: (a -> b) -> [a] -> [b] on map(f, xs)

   tell mReturn(f)
       set lng to length of xs
       set lst to {}
       repeat with i from 1 to lng
           set end of lst to |λ|(item i of xs, i, xs)
       end repeat
       return lst
   end tell

end map

-- 'The mapAccumL function behaves like a combination of map and foldl; -- it applies a function to each element of a list, passing an -- accumulating parameter from left to right, and returning a final -- value of this accumulator together with the new list.' (see Hoogle)

-- mapAccumL :: (acc -> x -> (acc, y)) -> acc -> [x] -> (acc, [y]) on mapAccumL(f, acc, xs)

   script
       on |λ|(a, x)
           tell mReturn(f) to set pair to |λ|(item 1 of a, x)
           [item 1 of pair, (item 2 of a) & {item 2 of pair}]
       end |λ|
   end script
   
   foldl(result, [acc, []], xs)

end mapAccumL

-- min :: Ord a => a -> a -> a on min(x, y)

   if y < x then
       y
   else
       x
   end if

end min

-- Lift 2nd class handler function into 1st class script wrapper -- mReturn :: Handler -> Script on mReturn(f)

   if class of f is script then
       f
   else
       script
           property |λ| : f
       end script
   end if

end mReturn

-- Egyptian multiplication - progressively doubling a list, appending -- stages of doubling to an accumulator where needed for binary -- assembly of a target length

-- replicate :: Int -> a -> [a] on replicate(n, a)

   set out to {}
   if n < 1 then return out
   set dbl to {a}
   
   repeat while (n > 1)
       if (n mod 2) > 0 then set out to out & dbl
       set n to (n div 2)
       set dbl to (dbl & dbl)
   end repeat
   return out & dbl

end replicate

-- snd :: (a, b) -> b on snd(xs)

   if class of xs is list and length of xs > 1 then
       item 2 of xs
   else
       missing value
   end if

end snd

-- show :: a -> String on show(e)

   set c to class of e
   if c = list then
       script serialized
           on |λ|(v)
               show(v)
           end |λ|
       end script
       
       "{" & intercalate(", ", map(serialized, e)) & "}"
   else if c = record then
       script showField
           on |λ|(kv)
               set {k, v} to kv
               k & ":" & show(v)
           end |λ|
       end script
       
       "{" & intercalate(", ", ¬
           map(showField, zip(allKeys(e), allValues(e)))) & "}"
   else if c = date then
       ("date \"" & e as text) & "\""
   else if c = text then
       "\"" & e & "\""
   else
       try
           e as text
       on error
           ("«" & c as text) & "»"
       end try
   end if

end show

-- succ :: Int -> Int on succ(x)

   x + 1

end succ

-- unlines :: [String] -> String on unlines(xs)

   intercalate(linefeed, xs)

end unlines

-- zipWith :: (a -> b -> c) -> [a] -> [b] -> [c] on zipWith(f, xs, ys)

   set lng to min(length of xs, length of ys)
   set lst to {}
   tell mReturn(f)
       repeat with i from 1 to lng
           set end of lst to |λ|(item i of xs, item i of ys)
       end repeat
       return lst
   end tell

end zipWith</lang>

Output:
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15

  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105


Or, defining only the relationship between successive terms:

<lang applescript>-- floyd :: [Int] -> [Int] on floyd(xs)

   set n to succ(length of xs)
   if n < 2 then
       {1}
   else
       enumFromTo(succ(n * (pred(n)) div 2), n * (succ(n)) div 2)
   end if

end floyd


-- floydN :: Int -> Int on floydN(n)

   take(n, iterate(floyd, {1}))

end floydN


-- showFloyd :: Int -> String on showFloyd(xs)

   script
       on |λ|(ns)
           script
               on |λ|(n)
                   justifyRight(4, space, n as string)
               end |λ|
           end script
           concat(map(result, ns))
       end |λ|
   end script
   unlines(map(result, xs))

end showFloyd


-- TEST ------------------------------------------------------------- on run

   showFloyd(floydN(5))
   

end run


-- GENERIC ABSTRACTIONS ---------------------------------------

-- concat :: a -> [a] -- concat :: [String] -> String on concat(xs)

   set lng to length of xs
   if 0 < lng and string is class of (item 1 of xs) then
       set acc to ""
   else
       set acc to {}
   end if
   repeat with i from 1 to lng
       set acc to acc & item i of xs
   end repeat
   acc

end concat

-- enumFromTo :: Int -> Int -> [Int] on enumFromTo(m, n)

   if m ≤ n then
       set lst to {}
       repeat with i from m to n
           set end of lst to i
       end repeat
       return lst
   else
       return {}
   end if

end enumFromTo

-- iterate :: (a -> a) -> a -> Gen [a] on iterate(f, x)

   script
       property v : missing value
       property g : mReturn(f)'s |λ|
       on |λ|()
           if missing value is v then
               set v to x
           else
               set v to g(v)
           end if
           return v
       end |λ|
   end script

end iterate


-- justifyRight :: Int -> Char -> String -> String on justifyRight(n, cFiller, strText)

   if n > length of strText then
       text -n thru -1 of ((replicate(n, cFiller) as text) & strText)
   else
       strText
   end if

end justifyRight


-- length :: [a] -> Int on |length|(xs)

   set c to class of xs
   if list is c or string is c then
       length of xs
   else
       (2 ^ 29 - 1) -- (maxInt - simple proxy for non-finite)
   end if

end |length|

-- map :: (a -> b) -> [a] -> [b] on map(f, xs)

   tell mReturn(f)
       set lng to length of xs
       set lst to {}
       repeat with i from 1 to lng
           set end of lst to |λ|(item i of xs, i, xs)
       end repeat
       return lst
   end tell

end map

-- min :: Ord a => a -> a -> a on min(x, y)

   if y < x then
       y
   else
       x
   end if

end min

-- Lift 2nd class handler function into 1st class script wrapper -- mReturn :: First-class m => (a -> b) -> m (a -> b) on mReturn(f)

   if class of f is script then
       f
   else
       script
           property |λ| : f
       end script
   end if

end mReturn

-- pred :: Int -> Int on pred(x)

   (-1) + x

end pred

-- Egyptian multiplication - progressively doubling a list, appending -- stages of doubling to an accumulator where needed for binary -- assembly of a target length -- replicate :: Int -> a -> [a] on replicate(n, a)

   set out to {}
   if n < 1 then return out
   set dbl to {a}
   
   repeat while (n > 1)
       if (n mod 2) > 0 then set out to out & dbl
       set n to (n div 2)
       set dbl to (dbl & dbl)
   end repeat
   return out & dbl

end replicate

-- succ :: Int -> Int on succ(x)

   1 + x

end succ

-- take :: Int -> [a] -> [a] -- take :: Int -> String -> String on take(n, xs)

   set c to class of xs
   if list is c then
       if 0 < n then
           items 1 thru min(n, length of xs) of xs
       else
           {}
       end if
   else if string is c then
       if 0 < n then
           text 1 thru min(n, length of xs) of xs
       else
           ""
       end if
   else if script is c then
       set ys to {}
       repeat with i from 1 to n
           set v to xs's |λ|()
           if missing value is v then
               return ys
           else
               set end of ys to v
           end if
       end repeat
       return ys
   else
       missing value
   end if

end take

-- unlines :: [String] -> String on unlines(xs)

   set {dlm, my text item delimiters} to ¬
       {my text item delimiters, linefeed}
   set str to xs as text
   set my text item delimiters to dlm
   str

end unlines</lang>

Output:
   1
   2   3
   4   5   6
   7   8   9  10
  11  12  13  14  15


Or as a partially populated matrix: <lang applescript>--------------------- FLOYD'S TRIANGLE -------------------

-- floyd :: Int -> Maybe Int on floyd(n)

   script go
       on |λ|(y, x)
           if x ≤ y then
               x + (y * (y - 1)) div 2
           else
               missing value
           end if
       end |λ|
   end script
   
   matrix(n, n, go)

end floyd



TEST -------------------------

on run

   -- Floyd triangles of dimensions 5 and 14
   
   unlines(map(compose(showMatrix, floyd), {5, 14}))
   

end run



GENERIC ------------------------

-- compose (<<<) :: (b -> c) -> (a -> b) -> a -> c on compose(f, g)

   script
       property mf : mReturn(f)
       property mg : mReturn(g)
       on |λ|(x)
           mf's |λ|(mg's |λ|(x))
       end |λ|
   end script

end compose


-- enumFromTo :: Int -> Int -> [Int] on enumFromTo(m, n)

   if m ≤ n then
       set xs to {}
       repeat with i from m to n
           set end of xs to i
       end repeat
       xs
   else
       {}
   end if

end enumFromTo


-- foldl :: (a -> b -> a) -> a -> [b] -> a on foldl(f, startValue, xs)

   tell mReturn(f)
       set v to startValue
       set lng to length of xs
       repeat with i from 1 to lng
           set v to |λ|(v, item i of xs, i, xs)
       end repeat
       return v
   end tell

end foldl


-- justifyRight :: Int -> Char -> String -> String on justifyRight(n, cFiller)

   script
       on |λ|(s)
           if n > length of s then
               text -n thru -1 of ((replicate(n, cFiller) as text) & s)
           else
               s
           end if
       end |λ|
   end script

end justifyRight


-- map :: (a -> b) -> [a] -> [b] on map(f, xs)

   -- The list obtained by applying f
   -- to each element of xs.
   tell mReturn(f)
       set lng to length of xs
       set lst to {}
       repeat with i from 1 to lng
           set end of lst to |λ|(item i of xs, i, xs)
       end repeat
       return lst
   end tell

end map


-- matrix :: Int -> Int -> ((Int, Int) -> a) -> a on matrix(nRows, nCols, f)

   -- A matrix of a given number of columns and rows,
   -- in which each value is a given function of its
   -- (zero-based) column and row indices.
   script go
       property g : mReturn(f)'s |λ|
       on |λ|(iRow)
           set xs to {}
           repeat with iCol from 1 to nCols
               set end of xs to g(iRow, iCol)
           end repeat
           xs
       end |λ|
   end script
   
   map(go, enumFromTo(1, nRows))

end matrix


-- max :: Ord a => a -> a -> a on max(x, y)

   if x > y then
       x
   else
       y
   end if

end max


-- mReturn :: First-class m => (a -> b) -> m (a -> b) on mReturn(f)

   -- 2nd class handler function lifted into 1st class script wrapper. 
   if script is class of f then
       f
   else
       script
           property |λ| : f
       end script
   end if

end mReturn


-- Egyptian multiplication - progressively doubling a list, appending -- stages of doubling to an accumulator where needed for binary -- assembly of a target length -- replicate :: Int -> String -> String on replicate(n, s)

   -- Egyptian multiplication - progressively doubling a list, 
   -- appending stages of doubling to an accumulator where needed 
   -- for binary assembly of a target length
   script p
       on |λ|({n})
           n ≤ 1
       end |λ|
   end script
   
   script f
       on |λ|({n, dbl, out})
           if (n mod 2) > 0 then
               set d to out & dbl
           else
               set d to out
           end if
           {n div 2, dbl & dbl, d}
       end |λ|
   end script
   
   set xs to |until|(p, f, {n, s, ""})
   item 2 of xs & item 3 of xs

end replicate


-- showMatrix :: Maybe a -> String on showMatrix(rows)

   -- String representation of rows
   -- as a matrix.
   
   script showRow
       on |λ|(a, row)
           set {maxWidth, prevRows} to a
           script showCell
               on |λ|(acc, cell)
                   set {w, xs} to acc
                   if missing value is cell then
                       {w, xs & ""}
                   else
                       set s to cell as string
                       {max(w, length of s), xs & s}
                   end if
               end |λ|
           end script
           
           set {rowMax, cells} to foldl(showCell, {0, {}}, row)
           {max(maxWidth, rowMax), prevRows & {cells}}
       end |λ|
   end script
   
   set {w, stringRows} to foldl(showRow, {0, {}}, rows)
   script go
       on |λ|(row)
           unwords(map(justifyRight(w, space), row))
       end |λ|
   end script
   
   unlines(map(go, stringRows)) & linefeed

end showMatrix


-- str :: a -> String on str(x)

   x as string

end str


-- unlines :: [String] -> String on unlines(xs)

   -- A single string formed by the intercalation
   -- of a list of strings with the newline character.
   set {dlm, my text item delimiters} to ¬
       {my text item delimiters, linefeed}
   set s to xs as text
   set my text item delimiters to dlm
   s

end unlines


-- until :: (a -> Bool) -> (a -> a) -> a -> a on |until|(p, f, x)

   set v to x
   set mp to mReturn(p)
   set mf to mReturn(f)
   repeat until mp's |λ|(v)
       set v to mf's |λ|(v)
   end repeat
   v

end |until|


-- unwords :: [String] -> String on unwords(xs)

   set {dlm, my text item delimiters} to ¬
       {my text item delimiters, space}
   set s to xs as text
   set my text item delimiters to dlm
   return s

end unwords</lang>

Output:
 1            
 2  3         
 4  5  6      
 7  8  9 10   
11 12 13 14 15

  1                                                    
  2   3                                                
  4   5   6                                            
  7   8   9  10                                        
 11  12  13  14  15                                    
 16  17  18  19  20  21                                
 22  23  24  25  26  27  28                            
 29  30  31  32  33  34  35  36                        
 37  38  39  40  41  42  43  44  45                    
 46  47  48  49  50  51  52  53  54  55                
 56  57  58  59  60  61  62  63  64  65  66            
 67  68  69  70  71  72  73  74  75  76  77  78        
 79  80  81  82  83  84  85  86  87  88  89  90  91    
 92  93  94  95  96  97  98  99 100 101 102 103 104 105

Straightforward

<lang applescript>on FloydsTriangle(n)

   set triangle to {}
   set i to 0
   repeat with w from 1 to n
       set row to {}
       repeat with i from (i + 1) to (i + w)
           set end of row to i
       end repeat
       set end of triangle to row
   end repeat
   
   return triangle

end FloydsTriangle

-- Task code: on matrixToText(matrix, w)

   script o
       property matrix : missing value
       property row : missing value
   end script
   
   set o's matrix to matrix
   set padding to "          "
   repeat with r from 1 to (count o's matrix)
       set o's row to o's matrix's item r
       repeat with i from 1 to (count o's row)
           set o's row's item i to text -w thru end of (padding & o's row's item i)
       end repeat
       set o's matrix's item r to join(o's row, "")
   end repeat
   
   return join(o's matrix, linefeed)

end matrixToText

on join(lst, delim)

   set astid to AppleScript's text item delimiters
   set AppleScript's text item delimiters to delim
   set txt to lst as text
   set AppleScript's text item delimiters to astid
   return txt

end join

local triangle5, text5, triangle14, text14 set triangle5 to FloydsTriangle(5) set text5 to matrixToText(triangle5, (count (end of end of triangle5 as text)) + 1) set triangle14 to FloydsTriangle(14) set text14 to matrixToText(triangle14, (count (end of end of triangle14 as text)) + 1) return linefeed & text5 & (linefeed & linefeed & text14 & linefeed)</lang>

Output:

<lang applescript>"

 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
  1
  2   3
  4   5   6
  7   8   9  10
 11  12  13  14  15
 16  17  18  19  20  21
 22  23  24  25  26  27  28
 29  30  31  32  33  34  35  36
 37  38  39  40  41  42  43  44  45
 46  47  48  49  50  51  52  53  54  55
 56  57  58  59  60  61  62  63  64  65  66
 67  68  69  70  71  72  73  74  75  76  77  78
 79  80  81  82  83  84  85  86  87  88  89  90  91
 92  93  94  95  96  97  98  99 100 101 102 103 104 105

"</lang>

Arturo

This example is incorrect. Please fix the code and remove this message.

Details: The last line should only have one space between values

<lang rebol>floyd: function [rowcount][

   result: new 1
   while [rowcount > size result][
       n: inc last last result
       row: new []
       loop n..n+size last result 'k -> 'row ++ @[k]
       'result ++ @[row]
   ]
   return result

]

loop [5 14] 'j [

   f: floyd j
   loop f 'row -> print map row 'r [pad to :string r 3]
   print ""

]</lang>

Output:
  1 
  2   3 
  4   5   6 
  7   8   9  10 
 11  12  13  14  15 

  1 
  2   3 
  4   5   6 
  7   8   9  10 
 11  12  13  14  15 
 16  17  18  19  20  21 
 22  23  24  25  26  27  28 
 29  30  31  32  33  34  35  36 
 37  38  39  40  41  42  43  44  45 
 46  47  48  49  50  51  52  53  54  55 
 56  57  58  59  60  61  62  63  64  65  66 
 67  68  69  70  71  72  73  74  75  76  77  78 
 79  80  81  82  83  84  85  86  87  88  89  90  91 
 92  93  94  95  96  97  98  99 100 101 102 103 104 105

AutoHotkey

<lang AutoHotkey>Floyds_triangle(row){ i = 0 loop %row% { n := A_Index loop, %n% { m := n, j := i, i++ while (m<row) j += m , m++ res .= spaces(StrLen(j+1)-StrLen(i) +(A_Index=1?0:1)) i } if (A_Index < row) res .= "`r`n" } return res } Spaces(no){ loop, % no res.=" " return % res }</lang> Examples:<lang AutoHotkey>MsgBox % Floyds_triangle(14)</lang>

Outputs:

 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35 36
37 38 39 40 41 42 43 44  45
46 47 48 49 50 51 52 53  54  55
56 57 58 59 60 61 62 63  64  65  66
67 68 69 70 71 72 73 74  75  76  77  78
79 80 81 82 83 84 85 86  87  88  89  90  91
92 93 94 95 96 97 98 99 100 101 102 103 104 105

AWK

<lang AWK>#!/bin/awk -f

BEGIN { if (rows !~ /^[0-9]+$/ || rows < 0) { print "invalid rows or missing from command line" print "syntax: awk -v rows=14 -f floyds_triangle.awk" exit 1 }

for (row=cols=1; row<=rows; row++ cols++) { width[row] = length(row + (rows * (rows-1))/2) for (col=1; col<=cols; col++) printf("%*d%c", width[col], ++n, row == col ? "\n" : " ") } } </lang>

output from: awk -f floyds_triangle.awk -v rows=5

 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15

output from: awk -f floyds_triangle.awk -v rows=14

 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35 36
37 38 39 40 41 42 43 44  45
46 47 48 49 50 51 52 53  54  55
56 57 58 59 60 61 62 63  64  65  66
67 68 69 70 71 72 73 74  75  76  77  78
79 80 81 82 83 84 85 86  87  88  89  90  91
92 93 94 95 96 97 98 99 100 101 102 103 104 105

BASIC

Applesoft BASIC

Line 150,160 creates a vector of the length of all entries is the last row. These values are used in line 210,220 to put the cursor at the correct horizontal position. <lang basic>

100 :
110  REM  FLOYD'S TRIANGLE
120 :
130  DEF  FN Q(A) =  INT ( LOG (A) /  LOG (10)) + 1                
140 N = 14
150  DIM P(N): P(0) =  - 1: FOR J = 1 TO N: I = (N * N - N) / 2 + J                              
160 P(J) = P(J - 1) + FN Q(I) + 1: NEXT J                          
200  FOR R = 1 TO N: FOR C = 1 TO R                                  
210 NR = NR + 1:COL = P(C) - ( FN Q(NR) - 1)                         
220  HTAB COL: PRINT NR;: NEXT C
230  PRINT : NEXT R                    

</lang>

Output:
]RUN
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
]RUN
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35 36
37 38 39 40 41 42 43 44  45
46 47 48 49 50 51 52 53  54  55
56 57 58 59 60 61 62 63  64  65  66
67 68 69 70 71 72 73 74  75  76  77  78
79 80 81 82 83 84 85 86  87  88  89  90  91
92 93 94 95 96 97 98 99 100 101 102 103 104 105

BASIC256

Works with: BASIC256 version 2.0.0.11

<lang BASIC256> function trianglevalue(col, row)

return (row-1)*row\2 + col

end function

subroutine printtriangle(numrows)

for row = 1 to numrows
 for col = 1 to row-1
  colwidth = length(""+trianglevalue(col, numrows))
  print right(" "*colwidth+trianglevalue(col, row), colwidth);" ";
 next col
 colwidth = length(""+trianglevalue(col, numrows))
 print right(" "*colwidth+trianglevalue(col, row), colwidth)
next row

end subroutine

call printtriangle(5) print call printtriangle(14) </lang>

Output:
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15

 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35 36
37 38 39 40 41 42 43 44  45
46 47 48 49 50 51 52 53  54  55
56 57 58 59 60 61 62 63  64  65  66
67 68 69 70 71 72 73 74  75  76  77  78
79 80 81 82 83 84 85 86  87  88  89  90  91
92 93 94 95 96 97 98 99 100 101 102 103 104 105

BBC BASIC

<lang bbcbasic> n = 14

     num = 1
     last = (n^2 - n + 2) DIV 2
     FOR row = 1 TO n
       col = last
       FOR num = num TO num + row - 1
         @% = LEN(STR$(col)) + 1 : REM set column width
         PRINT num ;
         col += 1
       NEXT
       PRINT
     NEXT row</lang>

Output for n = 5:

  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15

Output for n = 14:

  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

Commodore BASIC

<lang basic>100 print chr$(14);chr$(147);"Floyd's triangle" 110 print "How many rows? "; 120 open 1,0:input#1,ro$:close 1:print 130 ro=val(ro$):if ro<1 then 110 140 li=ro*(ro+1)/2 150 dim w(ro-1) 160 n=li-ro+1 170 for i=0 to ro-1:w(i)=len(str$(n)):n=n+1:next i 180 n=1 190 for i=1 to ro 200 : for j=0 to i-1 210 : n$=mid$(str$(n),2) 220 : if len(n$)<w(j) then for k=1 to w(j)-len(n$):print" ";:next k 230 : print n$; 240 : n=n+1 250 : next j 260 : print 270 next i 280 end</lang>

Output:
Floyd's triangle
How many rows? 5
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15

How many rows? 14
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

IS-BASIC

This example is incorrect. Please fix the code and remove this message.

Details: last line should only have one space between values

<lang IS-BASIC>100 PROGRAM "FloydT.bas" 110 LET N=14:LET J=1 120 TEXT 80 130 FOR I=1 TO N 140 FOR J=J TO J+I-1 150 PRINT USING " ###":J; 160 NEXT 170 PRINT 180 NEXT</lang>

MasmBasic

Builds with Masm, UAsm or AsmC plus the MasmBasic library <lang MasmBasic>include \masm32\MasmBasic\MasmBasic.inc

 SetGlobals rows, columns, ct, maxrows=4
 Init
 .Repeat

For_ rows=0 To maxrows For_ columns=0 To rows inc ct Print Str$("%__i", ct) .if columns>6 Print " " .endif Next Print Next Print Clr ct add maxrows, 9 ; 4+9=13

 .Until maxrows>13
 Inkey

EndOfCode</lang>

Output:

  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15

  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

QBasic

<lang QBasic>SUB FloydTriangle (fila)

   DIM numColum(fila)
   FOR colum = 1 TO fila
       numColum(colum) = LEN(STR$(colum + fila * (fila - 1) / 2))
   NEXT colum
   
   PRINT "output for "; STR$(fila): PRINT
   thisNum = 1
   FOR r = 1 TO fila
       FOR colum = 1 TO r
           PRINT RIGHT$("  " + STR$(thisNum), numColum(colum)); " ";
           thisNum = thisNum + 1
       NEXT colum
       PRINT
   NEXT

END SUB

FloydTriangle (5) PRINT FloydTriangle (14)</lang>

Yabasic

<lang freebasic>sub FloydTriangle (fila)

   dim numColum(fila)
   for colum = 1 to fila
       numColum(colum) = len(str$(colum + fila * (fila - 1) / 2))
   next colum
   
   print "output for ", str$(fila), "\n"
   thisNum = 1
   for r = 1 to fila
       for colum = 1 to r
           print right$("  " + str$(thisNum), numColum(colum)), " ";
           thisNum = thisNum + 1
       next colum
       print
   next

end sub

FloydTriangle (5) print FloydTriangle (14)</lang>

Batch File

Translation of: QBasic

<lang dos>:: Floyd's triangle Task from Rosetta Code

Batch File Implementation

@echo off rem main thing setlocal enabledelayedexpansion call :floydtriangle 5 echo( call :floydtriangle 14 exit /b 0

floydtriangle

set "fila=%1" for /l %%c in (1,1,%fila%) do (

   set /a "lastRowNum=%%c+fila*(fila-1)/2"
   rem count number of digits of whole number trick
   rem source: https://stackoverflow.com/a/45472269
   set /a "Log=1!lastRowNum:~1!-!lastRowNum:~1!-0"
   set /a "numColum[%%c]=!Log:0=+1!"

) echo(Output for %fila% set "thisNum=1" for /l %%r in (1,1,%fila%) do (

   set "printLine="
   for /l %%c in (1,1,%%r) do (
       rem count number of digits of whole number trick
       set /a "Log=1!thisNum:~1!-!thisNum:~1!-0"
       set /a "thisNumColum=!Log:0=+1!"
       rem handle spacing
       set "space= "
       set /a "extra=!numColum[%%c]!-!thisNumColum!"
       for /l %%s in (1,1,!extra!) do set "space=!space! "
       rem append current number to printLine
       set "printLine=!printLine!!space!!thisNum!"
       set /a "thisNum=!thisNum!+1"
   )
   echo(!printLine!

) goto :EOF</lang>

Output:
Output for 5
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15

Output for 14
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

BCPL

<lang bcpl>get "libhdr"

let width(n) = n<10 -> 1, 1 + width(n/10)

let floyd(rows) be $( let maxno = rows * (rows+1)/2

   let num = 1
   for r = 1 to rows
   $(  for c = 1 to r
       $(  writed(num, 1 + width(maxno-rows+c))
           num := num + 1
       $)
       wrch('*N')
   $)

$)

let start() be $( floyd(5)

   wrch('*N')
   floyd(14)

$)</lang>

Output:
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15

  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

Befunge

<lang Befunge>0" :seniL">:#,_&>:!#@_55+,:00p::1+*2/1v vv+1:\-1p01g5-\g00<v`*9"o"\+`"c"\`9:::_ $>>\:::9`\"c"`+\9v:>>+00g1-:00p5p1-00g^ <v\*84-\g01+`*"o"<^<<p00:+1\+1/2*+1:::\ ^>:#\1#,-#:\_$$.\:#^_$$>>1+\1-55+,:!#@_</lang>

Output:
Lines: 5

 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
Lines: 14

 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35 36
37 38 39 40 41 42 43 44  45
46 47 48 49 50 51 52 53  54  55
56 57 58 59 60 61 62 63  64  65  66
67 68 69 70 71 72 73 74  75  76  77  78
79 80 81 82 83 84 85 86  87  88  89  90  91
92 93 94 95 96 97 98 99 100 101 102 103 104 105

Bracmat

<lang bracmat> ( ( floyd

   =   lowerLeftCorner lastInColumn lastInRow row i W w
     .   put$(str$("Floyd " !arg ":\n"))
       &   !arg*(!arg+-1)*1/2+1
         : ?lowerLeftCorner
         : ?lastInColumn
       & 1:?lastInRow:?row:?i
       &   whl
         ' ( !row:~>!arg
           & @(!lastInColumn:? [?W)
           & @(!i:? [?w)
           & whl'(!w+1:~>!W:?w&put$" ")
           & put$!i
           & (   !i:<!lastInRow
               & put$" "
               & 1+!lastInColumn:?lastInColumn
             |   put$\n
               & (1+!row:?row)+!lastInRow:?lastInRow
               & !lowerLeftCorner:?lastInColumn
             )
           & 1+!i:?i
           )
   )
 & floyd$5
 & floyd$14
 );</lang>

Output:

Floyd 5:
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
Floyd 14:
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35 36
37 38 39 40 41 42 43 44  45
46 47 48 49 50 51 52 53  54  55
56 57 58 59 60 61 62 63  64  65  66
67 68 69 70 71 72 73 74  75  76  77  78
79 80 81 82 83 84 85 86  87  88  89  90  91
92 93 94 95 96 97 98 99 100 101 102 103 104 105

C

<lang c>#include <stdio.h>

void t(int n) { int i, j, c, len;

i = n * (n - 1) / 2; for (len = c = 1; c < i; c *= 10, len++); c -= i; // c is the col where width changes

  1. define SPEED_MATTERS 0
  2. if SPEED_MATTERS // in case we really, really wanted to print huge triangles often

char tmp[32], s[4096], *p;

sprintf(tmp, "%*d", len, 0);

inline void inc_numstr(void) { int k = len;

redo: if (!k--) return;

if (tmp[k] == '9') { tmp[k] = '0'; goto redo; }

if (++tmp[k] == '!') tmp[k] = '1'; }

for (p = s, i = 1; i <= n; i++) { for (j = 1; j <= i; j++) { inc_numstr(); __builtin_memcpy(p, tmp + 1 - (j >= c), len - (j < c)); p += len - (j < c);

*(p++) = (i - j)? ' ' : '\n';

if (p - s + len >= 4096) { fwrite(s, 1, p - s, stdout); p = s; } } }

fwrite(s, 1, p - s, stdout);

  1. else // NO_IT_DOESN'T

int num; for (num = i = 1; i <= n; i++) for (j = 1; j <= i; j++) printf("%*d%c", len - (j < c), num++, i - j ? ' ':'\n');

  1. endif

}

int main(void) { t(5), t(14);

// maybe not // t(10000); return 0; }</lang> Output identical to D's.

C#

Translation of: Perl

<lang csharp>using System; using System.Text;

public class FloydsTriangle {

   internal static void Main(string[] args)
   {
       int count;
       if (args.Length >= 1 && int.TryParse(args[0], out count) && count > 0)
       {
           Console.WriteLine(MakeTriangle(count));
       }
       else
       {
           Console.WriteLine(MakeTriangle(5));
           Console.WriteLine();
           Console.WriteLine(MakeTriangle(14));
       }
   }
   public static string MakeTriangle(int rows)
   {
       int maxValue = (rows * (rows + 1)) / 2;
       int digit = 0;
       StringBuilder output = new StringBuilder();
       for (int row = 1; row <= rows; row++)
       {
           for (int column = 0; column < row; column++)
           {
               int colMaxDigit = (maxValue - rows) + column + 1;
               if (column > 0)
               {
                   output.Append(' ');
               }
               digit++;
               output.Append(digit.ToString().PadLeft(colMaxDigit.ToString().Length));
           }
           output.AppendLine();
       }
       return output.ToString();
   }

}</lang>

C++

<lang cpp>

  1. include <windows.h>
  2. include <sstream>
  3. include <iostream>

//-------------------------------------------------------------------------------------------------- using namespace std;

//-------------------------------------------------------------------------------------------------- class floyds_tri { public:

   floyds_tri()  { lastLineLen = 0; }
   ~floyds_tri() { killArray(); }
   void create( int rows )
   {

_rows = rows; calculateLastLineLen(); display();

   }

private:

   void killArray()
   {

if( lastLineLen ) delete [] lastLineLen;

   }
   void calculateLastLineLen()
   {

killArray(); lastLineLen = new BYTE[_rows];

int s = 1 + ( _rows * ( _rows - 1 ) ) / 2;

for( int x = s, ix = 0; x < s + _rows; x++, ix++ ) { ostringstream cvr; cvr << x; lastLineLen[ix] = static_cast<BYTE>( cvr.str().size() ); }

   }
   void display()
   {

cout << endl << "Floyd\'s Triangle - " << _rows << " rows" << endl << "===============================================" << endl; int number = 1; for( int r = 0; r < _rows; r++ ) { for( int c = 0; c <= r; c++ ) { ostringstream cvr; cvr << number++; string str = cvr.str(); while( str.length() < lastLineLen[c] ) str = " " + str; cout << str << " "; } cout << endl; }

   }
   int _rows;
   BYTE* lastLineLen;

}; //-------------------------------------------------------------------------------------------------- int main( int argc, char* argv[] ) {

   floyds_tri t;
   int s;
   while( true )
   {

cout << "Enter the size of the triangle ( 0 to QUIT ): "; cin >> s; if( !s ) return 0; if( s > 0 ) t.create( s );

cout << endl << endl; system( "pause" );

   }
   return 0;

} //--------------------------------------------------------------------------------------------------</lang>

Output:
Floyd's Triangle - 5 rows
===============================================
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15


Floyd's Triangle - 14 rows
===============================================
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35 36
37 38 39 40 41 42 43 44  45
46 47 48 49 50 51 52 53  54  55
56 57 58 59 60 61 62 63  64  65  66
67 68 69 70 71 72 73 74  75  76  77  78
79 80 81 82 83 84 85 86  87  88  89  90  91
92 93 94 95 96 97 98 99 100 101 102 103 104 105

Clojure

I didn't translete this, it's from my own creation. <lang clojure> (defn TriangleList [n]

 (let [l (map inc (range))]
   (loop [l l x 1 nl []]
     (if (= n (count nl))
       nl
       (recur (drop x l) (inc x) (conj nl (take x l)))))))

(defn TrianglePrint [n]

 (let [t (TriangleList n)
       m (count (str (last (last t))))
       f (map #(map str %) t)
       l (map #(map (fn [x] (if (> m (count x))
                              (str (apply str (take (- m (count x))
                                                    (repeat " "))) x)
                              x)) %) f)
       e (map #(map (fn [x] (str " " x)) %) l)]
   (map #(println (apply str %)) e)))

</lang> By Average-user.

Output:
(TrianglePrint 5)
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15

(TrianglePrint 14)
   1
   2   3
   4   5   6
   7   8   9  10
  11  12  13  14  15
  16  17  18  19  20  21
  22  23  24  25  26  27  28
  29  30  31  32  33  34  35  36
  37  38  39  40  41  42  43  44  45
  46  47  48  49  50  51  52  53  54  55
  56  57  58  59  60  61  62  63  64  65  66
  67  68  69  70  71  72  73  74  75  76  77  78
  79  80  81  82  83  84  85  86  87  88  89  90  91
  92  93  94  95  96  97  98  99 100 101 102 103 104 105

CLU

<lang clu>floyd = cluster is triangle

   rep = null
   
   width = proc (n: int) returns (int)
       w: int := 1
       while n >= 10 do    
           w := w + 1
           n := n / 10
       end
       return (w)
   end width
   
   triangle = proc (rows: int) returns (string)
       ss: stream := stream$create_output()
       maxno: int := rows * (rows+1)/2
       num: int := 1
       for row: int in int$from_to(1, rows) do
           for col: int in int$from_to(1, row) do
               stream$putright(ss, int$unparse(num), 1 + width(maxno-rows+col))
               num := num + 1
           end
           stream$putl(ss, "")
       end
       return (stream$get_contents(ss))
   end triangle

end floyd

start_up = proc ()

   po: stream := stream$primary_output()
   stream$putl(po, floyd$triangle(5))
   stream$putl(po, floyd$triangle(14))

end start_up</lang>

Output:
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15

  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

COBOL

<lang cobol> IDENTIFICATION DIVISION.

       PROGRAM-ID. FLOYD-TRIANGLE.
       
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01 VARIABLES        COMP.
          02 NUM-LINES     PIC 99.
          02 CUR-LINE      PIC 99.
          02 CUR-COL       PIC 99.
          02 CUR-NUM       PIC 999.
          02 ZERO-SKIP     PIC 9.
          02 LINE-PTR      PIC 99.
          02 MAX-NUM       PIC 999.
       
       01 OUTPUT-FORMAT.
          02 OUT-LINE      PIC X(72).
          02 ONE-DIGIT     PIC B9.
          02 TWO-DIGITS    PIC BZ9.
          02 THREE-DIGITS  PIC BZZ9.
          02 MAX-COL-NUM   PIC 999.
       
       PROCEDURE DIVISION.
       BEGIN.
           MOVE 5 TO NUM-LINES. PERFORM FLOYD.
           DISPLAY ' '.
           MOVE 14 TO NUM-LINES. PERFORM FLOYD.
           STOP RUN.
           
       FLOYD.
           MOVE 1 TO CUR-NUM.
           COMPUTE MAX-NUM = NUM-LINES * (NUM-LINES + 1) / 2.
           PERFORM FLOYD-LINE 
               VARYING CUR-LINE FROM 1 BY 1
               UNTIL CUR-LINE IS GREATER THAN NUM-LINES.
           
       FLOYD-LINE.
           MOVE ' ' TO OUT-LINE.
           MOVE 1 TO LINE-PTR.
           PERFORM FLOYD-NUM
               VARYING CUR-COL FROM 1 BY 1
               UNTIL CUR-COL IS GREATER THAN CUR-LINE.
           DISPLAY OUT-LINE.
       FLOYD-NUM.
           COMPUTE MAX-COL-NUM = MAX-NUM - NUM-LINES + CUR-COL.
           MOVE 0 TO ZERO-SKIP.
           INSPECT MAX-COL-NUM TALLYING ZERO-SKIP FOR LEADING '0'.
           IF ZERO-SKIP IS EQUAL TO ZERO
               PERFORM FLOYD-THREE-DIGITS
           ELSE IF ZERO-SKIP IS EQUAL TO 1
               PERFORM FLOYD-TWO-DIGITS
           ELSE IF ZERO-SKIP IS EQUAL TO 2
               PERFORM FLOYD-ONE-DIGIT.
           ADD 1 TO CUR-NUM.
               
       FLOYD-ONE-DIGIT.
           MOVE CUR-NUM TO ONE-DIGIT.
           STRING ONE-DIGIT DELIMITED BY SIZE INTO OUT-LINE
               WITH POINTER LINE-PTR.
       
       FLOYD-TWO-DIGITS.
           MOVE CUR-NUM TO TWO-DIGITS.
           STRING TWO-DIGITS DELIMITED BY SIZE INTO OUT-LINE
               WITH POINTER LINE-PTR.
       
       FLOYD-THREE-DIGITS.
           MOVE CUR-NUM TO THREE-DIGITS.
           STRING THREE-DIGITS DELIMITED BY SIZE INTO OUT-LINE
               WITH POINTER LINE-PTR.</lang>
Output:
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15

  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

CoffeeScript

Translation of: Kotlin

<lang coffeescript>triangle = (array) -> for n in array

   console.log "#{n} rows:"
   printMe = 1
   printed = 0
   row = 1
   to_print = ""
   while row <= n
       cols = Math.ceil(Math.log10(n * (n - 1) / 2 + printed + 2.0))
       p = ("" + printMe).length
       while p++ <= cols
           to_print += ' '
       to_print += printMe + ' '
       if ++printed == row
           console.log to_print
           to_print = ""
           row++
           printed = 0
       printMe++

triangle [5, 14]</lang> Output as Kotlin.

Common Lisp

Version 1

<lang lisp>;;;using flet to define local functions and storing precalculated column widths in array

verbose, but more readable and efficient than version 2

(defun floydtriangle (rows)

      (let (column-widths)
        (setf column-widths (make-array rows :initial-element nil))
          (flet (
            (lazycat (n)
             (/ (+ (expt n 2) n 2) 2))
            (width (v)
             (+ 1 (floor (log v 10)))))
           (dotimes (i rows)
            (setf (aref column-widths i)(width (+ i (lazycat (- rows 1))))))
           (dotimes (row rows)
            (dotimes (col (+ 1 row))
              (format t "~vd " (aref column-widths col)(+ col (lazycat row))))
            (format t "~%")))))</lang>

Version 2 - any base

<lang lisp>;;; more concise than version 1 but less efficient for a large triangle

optional "base" parameter will allow use of any base from 2 to 36

(defun floydtriangle (rows &optional (base 10))

      (dotimes (row rows)
        (dotimes (column (+ 1 row))
          (format t "~v,vr " base (length (format nil "~vr" base (+ column (/ (+ (expt (- rows 1) 2) (- rows 1) 2) 2)))) (+ column (/ (+ (expt row 2) row 2) 2))))
        (format t "~%")))</lang>
Output:
(floydtriangle 5)
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15

(floydtriangle 14)
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35 36
37 38 39 40 41 42 43 44  45
46 47 48 49 50 51 52 53  54  55
56 57 58 59 60 61 62 63  64  65  66
67 68 69 70 71 72 73 74  75  76  77  78
79 80 81 82 83 84 85 86  87  88  89  90  91
92 93 94 95 96 97 98 99 100 101 102 103 104 105

(floydtriangle 5 2)
   1 
  10   11 
 100  101  110 
 111 1000 1001 1010 
1011 1100 1101 1110 1111 

(floydtriangle 14 36)
 1 
 2  3 
 4  5  6 
 7  8  9  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 10 
11 12 13 14 15 16 17 18 19 
1A 1B 1C 1D 1E 1F 1G 1H 1I 1J 
1K 1L 1M 1N 1O 1P 1Q 1R 1S 1T 1U 
1V 1W 1X 1Y 1Z 20 21 22 23 24 25 26 
27 28 29 2A 2B 2C 2D 2E 2F 2G 2H 2I 2J 
2K 2L 2M 2N 2O 2P 2Q 2R 2S 2T 2U 2V 2W 2X

Cowgol

<lang cowgol>include "cowgol.coh";

sub width(n: uint16): (w: uint8) is

   w := 1;
   while n >= 10 loop
       n := n / 10;
       w := w + 1;
   end loop;

end sub;

sub print_fixed(n: uint16, w: uint8) is

   w := w - width(n);
   while w > 0 loop
       print_char(' ');
       w := w - 1;
   end loop;
   print_i16(n);

end sub;

sub floyd(rows: uint16) is

   var maxno := rows * (rows+1)/2;
   var num: uint16 := 1;
   var row: uint16 := 1;
   while row <= rows loop
       var col: uint16 := 1;
       while col <= row loop
           print_fixed(num, 1 + width(maxno - rows + col));
           num := num + 1;
           col := col + 1;
       end loop;
       print_nl();
       row := row + 1;
   end loop;

end sub;

floyd(5); print_nl(); floyd(14);</lang>

Output:
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15

  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

D

<lang d>import std.stdio, std.conv;

void floydTriangle(in uint n) {

   immutable lowerLeftCorner = n * (n - 1) / 2 + 1;
   foreach (r; 0 .. n)
       foreach (c; 0 .. r + 1)
           writef("%*d%c",
                  text(lowerLeftCorner + c).length,
                  r * (r + 1) / 2 + c + 1,
                  c == r ? '\n' : ' ');

}

void main() {

   floydTriangle(5);
   floydTriangle(14);

}</lang>

Output:
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35 36
37 38 39 40 41 42 43 44  45
46 47 48 49 50 51 52 53  54  55
56 57 58 59 60 61 62 63  64  65  66
67 68 69 70 71 72 73 74  75  76  77  78
79 80 81 82 83 84 85 86  87  88  89  90  91
92 93 94 95 96 97 98 99 100 101 102 103 104 105

Elixir

<lang elixir>defmodule Floyd do

 def triangle(n) do
   max = trunc(n * (n + 1) / 2)
   widths = for m <- (max - n + 1)..max, do: (m |> Integer.to_string |> String.length) + 1
   format = Enum.map(widths, fn wide -> "~#{wide}w" end) |> List.to_tuple
   line(n, 0, 1, format)
 end
 
 def line(n, n, _, _), do: :ok
 def line(n, i, count, format) do
   Enum.each(0..i, fn j -> :io.fwrite(elem(format,j), [count+j]) end)
   IO.puts ""
   line(n, i+1, count+i+1, format)
 end

end

Floyd.triangle(5) Floyd.triangle(14)</lang>

Output:
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

Erlang

<lang erlang> -module( floyds_triangle ).

-export( [integers/1, print/1, strings/1, task/0] ).

integers( N ) ->

         lists:reverse( integers_reversed(N) ).

print( N ) ->

      [io:fwrite("~s~n", [lists:flatten(X)]) || X <- strings(N)].

strings( N ) ->

       Strings_reversed = [strings_from_integers(X) || X <- integers_reversed(N)],
       Paddings = paddings( [lengths(X) || X <- Strings_reversed] ),
       [formats(X, Y) || {X, Y} <- lists:zip(Paddings, lists:reverse(Strings_reversed))].

task() ->

      print( 5	),
      print( 14 ).


formats( Paddings, Strings ) -> [lists:flatten(io_lib:format(" ~*s", [X, Y])) || {X, Y} <- lists:zip(Paddings, Strings)].

integers_reversed( N ) ->

         {_End, Integers_reversed} = lists:foldl( fun integers_reversed/2, {1, []}, lists:seq(0, N - 1) ),
         Integers_reversed.

integers_reversed( N, {Start, Acc} ) ->

         End = Start + N,
         {End + 1, [lists:seq(Start, End) | Acc]}.

lengths( Strings ) -> [string:len(X) || X <- Strings].

paddings( [Last_line | T] ) ->

         {[], Paddings} = lists:foldl( fun paddings/2, {paddings_lose_last(Last_line), [Last_line]}, lists:seq(1, erlang:length(T)) ),
         Paddings.

paddings( _N, {Current, Acc} ) -> {paddings_lose_last(Current), [Current | Acc]}.

paddings_lose_last( List ) -> [_H | T] = lists:reverse( List ), lists:reverse( T ).

strings_from_integers( Integers ) -> [erlang:integer_to_list(X) || X <- Integers]. </lang>

Output:
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

ERRE

<lang ERRE> PROGRAM FLOYD

! ! for rosettacode.org !

BEGIN

 N=14
 NUM=1
 LAST=(N^2-N+2) DIV 2
 FOR ROW=1 TO N DO
   FOR J=1 TO ROW DO
      US$=STRING$(LEN(STR$(LAST-1+J))-1,"#")
      WRITE(US$;NUM;)
      PRINT(" ";)
      NUM+=1
   END FOR
   PRINT
 END FOR

END PROGRAM </lang> Example for n=14

Output:
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35 36
37 38 39 40 41 42 43 44  45
46 47 48 49 50 51 52 53  54  55
56 57 58 59 60 61 62 63  64  65  66
67 68 69 70 71 72 73 74  75  76  77  78
79 80 81 82 83 84 85 86  87  88  89  90  91
92 93 94 95 96 97 98 99 100 101 102 103 104 105

Excel

LAMBDA

We can define this declaratively in Excel by binding the name floydTriangle to the following lambda expression in the Name Manager of the Excel WorkBook:

(See LAMBDA: The ultimate Excel worksheet function)

<lang lisp>floydTriangle =LAMBDA(n,

   IF(0 < n,
       LET(
           ixs, SEQUENCE(
               n, n, 
               0, 1
           ),
           x, MOD(ixs, n),
           y, QUOTIENT(ixs, n),
           
           IF(x > y,
               "",
               x + 1 + QUOTIENT(
                   y * (1 + y), 
                   2
               )
           )
       ),
       ""
   )

)</lang>

Output:

The formula in cell B2, for example, defines an array which populates the whole range B2:F6

fx =floydTriangle(A2)
A B C D E F G H I J K L M N O
1 Row count
2 5 1
3 2 3
4 4 5 6
5 7 8 9 10
6 11 12 13 14 15
7 14 1
8 2 3
9 4 5 6
10 7 8 9 10
11 11 12 13 14 15
12 16 17 18 19 20 21
13 22 23 24 25 26 27 28
14 29 30 31 32 33 34 35 36
15 37 38 39 40 41 42 43 44 45
16 46 47 48 49 50 51 52 53 54 55
17 56 57 58 59 60 61 62 63 64 65 66
18 67 68 69 70 71 72 73 74 75 76 77 78
19 79 80 81 82 83 84 85 86 87 88 89 90 91
20 92 93 94 95 96 97 98 99 100 101 102 103 104 105

F#

<lang fsharp>open System

[<EntryPoint>] let main argv =

   // columns and rows are 0-based, so the input has to be decremented:
   let maxRow =
       match UInt32.TryParse(argv.[0]) with
       | (true, v) when v > 0u -> int (v - 1u)
       | (_, _) -> failwith "not a positive integer"
   let len (n: int) = int (Math.Floor(Math.Log10(float n)))
   let col0 row = row * (row + 1) / 2 + 1
   let col0maxRow = col0 maxRow
   for row in [0 .. maxRow] do
       for col in [0 .. row] do
           let value = (col0 row) + col
           let pad = String(' ', (len (col0maxRow + col) - len (value) + 1))
           printf "%s%d" pad value
       printfn ""
   0</lang>

Output for 5 and 14 (via command line argument)

  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

Factor

<lang factor>USING: io kernel math math.functions math.ranges prettyprint sequences ; IN: rosetta-code.floyds-triangle

floyd. ( n -- )
   [ dup 1 - * 2 / 1 + dup 1 ] [ [1,b] ] bi
   [
       [
           2dup [ log10 1 + >integer ] bi@ -
           [ " " write ] times dup pprint bl [ 1 + ] bi@
       ] times nl [ drop dup ] dip
   ] each nl 3drop ;

5 14 [ floyd. ] bi@</lang>

Output:
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 

 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 
16 17 18 19 20 21 
22 23 24 25 26 27 28 
29 30 31 32 33 34 35 36 
37 38 39 40 41 42 43 44  45 
46 47 48 49 50 51 52 53  54  55 
56 57 58 59 60 61 62 63  64  65  66 
67 68 69 70 71 72 73 74  75  76  77  78 
79 80 81 82 83 84 85 86  87  88  89  90  91 
92 93 94 95 96 97 98 99 100 101 102 103 104 105 

Forth

<lang forth>: lastn ( rows -- n ) dup 1- * 2/ ;

width ( n -- n ) s>f flog ftrunc f>s 2 + ;
triangle ( rows -- )
 dup lastn 0 rot ( last 0 rows )
 0 do
   over cr
   i 1+ 0 do
     1+ swap 1+ swap
     2dup width u.r
   loop
   drop
 loop
 2drop ;

</lang>

Fortran

Please find compilation instructions on GNU/linux system at the beginning of the source. There, also, are the example output triangles produced by running the program. The environment variable setting and command line argument are vestigial. Ignore them. The code demonstrates writing to an in memory buffer, an old feature of FORTRAN. <lang FORTRAN> !-*- mode: compilation; default-directory: "/tmp/" -*- !Compilation started at Tue May 21 22:55:08 ! !a=./f && make $a && OMP_NUM_THREADS=2 $a 1223334444 !gfortran -std=f2008 -Wall -ffree-form -fall-intrinsics f.f08 -o f ! 1 ! 2 3 ! 4 5 6 ! 7 8 9 10 ! 11 12 13 14 15 ! ! ! 1 ! 2 3 ! 4 5 6 ! 7 8 9 10 ! 11 12 13 14 15 ! 16 17 18 19 20 21 ! 22 23 24 25 26 27 28 ! 29 30 31 32 33 34 35 36 ! 37 38 39 40 41 42 43 44 45 ! 46 47 48 49 50 51 52 53 54 55 ! 56 57 58 59 60 61 62 63 64 65 66 ! 67 68 69 70 71 72 73 74 75 76 77 78 ! 79 80 81 82 83 84 85 86 87 88 89 90 91 ! 92 93 94 95 96 97 98 99 100 101 102 103 104 105 ! ! ! !Compilation finished at Tue May 21 22:55:08


program p

 integer, dimension(2) :: examples = [5, 14]
 integer :: i
 do i=1, size(examples)
   call floyd(examples(i))
   write(6, '(/)')
 end do

contains

 subroutine floyd(rows)
   integer, intent(in) :: rows
   integer :: n, i, j, k
   integer, dimension(60) :: L
   character(len=504) :: fmt
   n = (rows*(rows+1))/2 ! Gauss's formula
   do i=1,rows ! compute format of final row
     L(i) = 2+int(log10(real(n-rows+i)))
   end do
   k = 0
   do i=1,rows
     do j=1,i
       k = k+1
       write(fmt,'(a2,i1,a1)')'(i',L(j),')'
       write(6,fmt,advance='no') k
     enddo
     write(6,*) 
   end do
 end subroutine floyd
 

end program p </lang>

FreeBASIC

<lang freebasic>' version 19-09-2015 ' compile with: fbc -s console

Sub pascal_triangle(n As UInteger)

   Dim As UInteger a = 1, b, i, j, switch = n + 1
   Dim As String frmt, frmt_1, frmt_2
   ' last number of the last line
   i = (n * (n + 1)) \ 2
   frmt_2 = String(Len(Str(i)) + 1, "#")
   ' first number of the last line
   i = ((n - 1) * n) \ 2 + 1
   frmt_1 = String(Len(Str(i)) + 1, "#")
   ' we have 2 different formats strings
   ' find the point where we have to make the switch
   If frmt_1 <> frmt_2 Then
       j = i + 1
       While Len(Str(i)) = Len(Str(J))
           j =  j + 1
       Wend
       switch = j - i
   End If
   Print "output for "; Str(n) : Print
   For i = 1 To n
       frmt = frmt_1
       b = (i * (i + 1)) \ 2
       For j = a To b
           ' if we have the switching point change format string
           If j - a = switch Then frmt = frmt_2
           Print Using frmt; j;
       Next j
       Print
       a = b + 1
   Next i
   Print

End Sub

' ------=< MAIN >=------

pascal_triangle(5)

pascal_triangle(14)


' empty keyboard buffer While Inkey <> "" : Wend Print : Print "hit any key to end program" Sleep End</lang>

Output:
output for 5             output for 14  
                         
  1                        1
  2  3                     2  3
  4  5  6                  4  5  6
  7  8  9 10               7  8  9 10
 11 12 13 14 15           11 12 13 14 15
                          16 17 18 19 20 21
                          22 23 24 25 26 27 28
                          29 30 31 32 33 34 35 36
                          37 38 39 40 41 42 43 44  45
                          46 47 48 49 50 51 52 53  54  55
                          56 57 58 59 60 61 62 63  64  65  66
                          67 68 69 70 71 72 73 74  75  76  77  78
                          79 80 81 82 83 84 85 86  87  88  89  90  91
                          92 93 94 95 96 97 98 99 100 101 102 103 104 105

Gambas

Click this link to run this code <lang gambas>Public Sub Main() Dim siCount, siNo, siCounter As Short Dim siLine As Short = 1 Dim siInput As Short[] = [5, 14]

For siCount = 0 To siInput.Max

 Print "Floyd's triangle to " & siInput[siCount] & " lines"
 Do
   Inc siNo
   Inc siCounter
   Print Format(siNo, "####");
     If siLine = siCounter Then 
       Print 
       Inc siLine
       siCounter = 0
     End If
   If siLine - 1 = siInput[siCount] Then Break
 Loop
 siLine = 1
 siCounter = 0
 siNo = 0
 Print

Next

End</lang> Output:

Floyd's triangle to 5 lines
   1
   2   3
   4   5   6
   7   8   9  10
  11  12  13  14  15

Floyd's triangle to 14 lines
   1
   2   3
   4   5   6
   7   8   9  10
  11  12  13  14  15
  16  17  18  19  20  21
  22  23  24  25  26  27  28
  29  30  31  32  33  34  35  36
  37  38  39  40  41  42  43  44  45
  46  47  48  49  50  51  52  53  54  55
  56  57  58  59  60  61  62  63  64  65  66
  67  68  69  70  71  72  73  74  75  76  77  78
  79  80  81  82  83  84  85  86  87  88  89  90  91
  92  93  94  95  96  97  98  99 100 101 102 103 104 105

Go

<lang go>package main

import "fmt"

func main() {

   floyd(5)
   floyd(14)

}

func floyd(n int) {

   fmt.Printf("Floyd %d:\n", n)
   lowerLeftCorner := n*(n-1)/2 + 1
   lastInColumn := lowerLeftCorner
   lastInRow := 1
   for i, row := 1, 1; row <= n; i++ {
       w := len(fmt.Sprint(lastInColumn))
       if i < lastInRow {
           fmt.Printf("%*d ", w, i)
           lastInColumn++
       } else {
           fmt.Printf("%*d\n", w, i)
           row++
           lastInRow += row
           lastInColumn = lowerLeftCorner
       }
   }

}</lang>

Output:
Floyd 5:
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
Floyd 14:
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35 36
37 38 39 40 41 42 43 44  45
46 47 48 49 50 51 52 53  54  55
56 57 58 59 60 61 62 63  64  65  66
67 68 69 70 71 72 73 74  75  76  77  78
79 80 81 82 83 84 85 86  87  88  89  90  91
92 93 94 95 96 97 98 99 100 101 102 103 104 105

Groovy

Translation of: Java

<lang groovy>class Floyd {

   static void main(String[] args) {
       printTriangle(5)
       printTriangle(14)
   }
   private static void printTriangle(int n) {
       println(n + " rows:")
       int printMe = 1
       int numsPrinted = 0
       for (int rowNum = 1; rowNum <= n; printMe++) {
           int cols = (int) Math.ceil(Math.log10(n * (n - 1) / 2 + numsPrinted + 2))
           printf("%" + cols + "d ", printMe)
           if (++numsPrinted == rowNum) {
               println()
               rowNum++
               numsPrinted = 0
           }
       }
   }

}</lang>

Output:
5 rows:
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 
14 rows:
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 
16 17 18 19 20 21 
22 23 24 25 26 27 28 
29 30 31 32 33 34 35 36 
37 38 39 40 41 42 43 44  45 
46 47 48 49 50 51 52 53  54  55 
56 57 58 59 60 61 62 63  64  65  66 
67 68 69 70 71 72 73 74  75  76  77  78 
79 80 81 82 83 84 85 86  87  88  89  90  91 
92 93 94 95 96 97 98 99 100 101 102 103 104 105 

Haskell

<lang haskell>--------------------- FLOYDS TRIANGLE --------------------

floydTriangle :: Int floydTriangle =

 ( zipWith
     (fmap (.) enumFromTo <*> (\a b -> pred (a + b)))
     <$> scanl (+) 1
     <*> id
 )
   [1 ..]



TEST -------------------------

main :: IO () main = mapM_ (putStrLn . formatFT) [5, 14]


DISPLAY ------------------------

formatFT :: Int -> String formatFT n = unlines $ unwords . zipWith alignR ws <$> t

 where
   t = take n floydTriangle
   ws = length . show <$> last t

alignR :: Int -> Int -> String alignR n =

 ( (<>)
     =<< flip replicate ' '
       . (-) n
       . length
 )
   . show</lang>
Output:
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15

 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35 36
37 38 39 40 41 42 43 44  45
46 47 48 49 50 51 52 53  54  55
56 57 58 59 60 61 62 63  64  65  66
67 68 69 70 71 72 73 74  75  76  77  78
79 80 81 82 83 84 85 86  87  88  89  90  91
92 93 94 95 96 97 98 99 100 101 102 103 104 105


Or, simplifying a little by delegating the recursion scheme to mapAccumL

<lang haskell>import Control.Monad ((>=>)) import Data.List (mapAccumL)


FLOYD'S TRIANGLE -------------------

floyd :: Int -> Int floyd n =

 snd $
   mapAccumL
     (\a x -> ((,) . succ <*> enumFromTo a) (a + x))
     1
     [0 .. pred n]

TEST -------------------------

main :: IO () main = mapM_ putStrLn $ showFloyd . floyd <$> [5, 14]

showFloyd :: Int -> String showFloyd x =

 let padRight n = (drop . length) <*> (replicate n ' ' <>)
  in unlines
       ( fmap
           ( zipWith
               (\n v -> padRight n (show v))
               (fmap (succ . length . show) (last x))
               >=> id
           )
           x
       )</lang>
Output:
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15

  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105


Or, defining just the relationship between successive terms: <lang haskell>----------------- LINES OF FLOYDS TRIANGLE ---------------

floyds :: Int floyds = iterate floyd [1]

floyd :: [Int] -> [Int] floyd xs

 | n < 2 = [1]
 | otherwise =
   [ succ (div (n * pred n) 2)
     .. div (n * succ n) 2
   ]
 where
   n = succ (length xs)



TEST -------------------------

main :: IO () main = do

 mapM_ print $ take 5 floyds
 putStrLn ""
 mapM_ print $ take 14 floyds</lang>
Output:
[1]
[2,3]
[4,5,6]
[7,8,9,10]
[11,12,13,14,15]

[1]
[2,3]
[4,5,6]
[7,8,9,10]
[11,12,13,14,15]
[16,17,18,19,20,21]
[22,23,24,25,26,27,28]
[29,30,31,32,33,34,35,36]
[37,38,39,40,41,42,43,44,45]
[46,47,48,49,50,51,52,53,54,55]
[56,57,58,59,60,61,62,63,64,65,66]
[67,68,69,70,71,72,73,74,75,76,77,78]
[79,80,81,82,83,84,85,86,87,88,89,90,91]
[92,93,94,95,96,97,98,99,100,101,102,103,104,105]


Or as a partially populated matrix:

<lang haskell>import Control.Monad (join) import Data.Matrix (Matrix, getElem, matrix, nrows, toLists)


FLOYDS TRIANGLE --------------------

floyd :: Int -> Matrix (Maybe Int) floyd n = matrix n n go

 where
   go (y, x)
     | x > y = Nothing
     | otherwise = Just (x + quot (pred y * y) 2)
     

TEST -------------------------

main :: IO () main = mapM_ putStrLn $ showFloyd . floyd <$> [5, 14]



DISPLAY ------------------------

showFloyd :: Matrix (Maybe Int) -> String showFloyd m =

 (unlines . fmap unwords . toLists) $
   go <$> m
 where
   go Nothing = ""
   go (Just n) = padRight w (show n)
   Just v = join getElem (nrows m) m
   w = length (show v)

padRight :: Int -> String -> String padRight n = (drop . length) <*> (replicate n ' ' <>)</lang>

Output:
 1    
 2  3   
 4  5  6  
 7  8  9 10 
11 12 13 14 15

  1             
  2   3            
  4   5   6           
  7   8   9  10          
 11  12  13  14  15         
 16  17  18  19  20  21        
 22  23  24  25  26  27  28       
 29  30  31  32  33  34  35  36      
 37  38  39  40  41  42  43  44  45     
 46  47  48  49  50  51  52  53  54  55    
 56  57  58  59  60  61  62  63  64  65  66   
 67  68  69  70  71  72  73  74  75  76  77  78  
 79  80  81  82  83  84  85  86  87  88  89  90  91 
 92  93  94  95  96  97  98  99 100 101 102 103 104 105

Icon and Unicon

The following solution works in both languages: <lang unicon>procedure main(a)

   n := integer(a[1]) | 5
   w := ((n*(n-1))/2)-n
   c := create seq()
   every row := 1 to n do {
       every col := 1 to row do {
           width := *(w+col)+1
           every writes(right(@c,width))
           }
       write()
       }

end</lang>

Sample outputs:

->ft
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
->
->ft 14
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105
->

J

Note: require 'strings' does nothing in J7, but is harmless (strings is already incorporated in J7).

<lang J>require 'strings' floyd=: [: rplc&(' 0';' ')"1@":@(* ($ $ +/\@,)) >:/~@:i.</lang>

Note, the parenthesis around ($ $ +/\@,) is optional, and only included for emphasis.

Example use:

<lang J> floyd 5

1            
2  3         
4  5  6      
7  8  9 10   

11 12 13 14 15

  floyd 14
1                                             
2  3                                          
4  5  6                                       
7  8  9 10                                    

11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105</lang>

How it works:

First, we create a square lower triangular matrix with our argument as the length of one side. We have 1s along the diagonal and the lower triangle, and 0s for the upper triangle.

Second, we create a running sum of these values (treating rows as being adjacent horizontally for this purpose). Then, we multiply this result by our lower triangular matrix (forcing the upper triangle to be 0s).

Then, we format the matrix as text (which gives us the required vertical alignment), and in each row we replace each space followed by a zero with two spaces.

Efficiency note: In a measurement of time used: in floyd 100, 80% the time here goes into the string manipulations -- sequential additions and multiplications are cheap. In floyd 1000 this jumps to 98% of the time. Here's a faster version (about 3x on floyd 1000) courtesy of Aai of the J forums:

<lang J>floyd=: [: ({.~ i.&1@E.~&' 0')"1@":@(* ($ $ +/\@,)) >:/~@:i.</lang>

Java

<lang java> public class Floyd { public static void main(String[] args){ printTriangle(5); printTriangle(14); }

private static void printTriangle(int n){ System.out.println(n + " rows:"); for(int rowNum = 1, printMe = 1, numsPrinted = 0; rowNum <= n; printMe++){ int cols = (int)Math.ceil(Math.log10(n*(n-1)/2 + numsPrinted + 2)); System.out.printf("%"+cols+"d ", printMe); if(++numsPrinted == rowNum){ System.out.println(); rowNum++; numsPrinted = 0; } } } }</lang> Output:

5 rows:
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 
14 rows:
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 
16 17 18 19 20 21 
22 23 24 25 26 27 28 
29 30 31 32 33 34 35 36 
37 38 39 40 41 42 43 44  45 
46 47 48 49 50 51 52 53  54  55 
56 57 58 59 60 61 62 63  64  65  66 
67 68 69 70 71 72 73 74  75  76  77  78 
79 80 81 82 83 84 85 86  87  88  89  90  91 
92 93 94 95 96 97 98 99 100 101 102 103 104 105 

JavaScript

ES5

(In a functional idiom of JavaScript)

Two main functions:

  1. An expression of the Floyd triangle as a list of lists (a function of the number of rows),
  2. and a mapping of that expression to a formatted string.

<lang JavaScript>(function () {

   'use strict';
   // FLOYD's TRIANGLE -------------------------------------------------------
   // floyd :: Int -> Int
   function floyd(n) {
       return snd(mapAccumL(function (start, row) {
           return [start + row + 1, enumFromTo(start, start + row)];
       }, 1, enumFromTo(0, n - 1)));
   };
   // showFloyd :: Int -> String
   function showFloyd(xss) {
       var ws = map(compose([succ, length, show]), last(xss));
       return unlines(map(function (xs) {
           return concat(zipWith(function (w, x) {
               return justifyRight(w, ' ', show(x));
           }, ws, xs));
       }, xss));
   };


   // GENERIC FUNCTIONS ------------------------------------------------------
   // compose :: [(a -> a)] -> (a -> a)
   function compose(fs) {
       return function (x) {
           return fs.reduceRight(function (a, f) {
               return f(a);
           }, x);
       };
   };
   // concat :: a -> [a] | [String] -> String
   function concat(xs) {
       if (xs.length > 0) {
           var unit = typeof xs[0] === 'string' ?  : [];
           return unit.concat.apply(unit, xs);
       } else return [];
   };
   // enumFromTo :: Int -> Int -> [Int]
   function enumFromTo(m, n) {
       return Array.from({
           length: Math.floor(n - m) + 1
       }, function (_, i) {
           return m + i;
       });
   };
   // justifyRight :: Int -> Char -> Text -> Text
   function justifyRight(n, cFiller, strText) {
       return n > strText.length ? (cFiller.repeat(n) + strText)
           .slice(-n) : strText;
   };
   // last :: [a] -> a
   function last(xs) {
       return xs.length ? xs.slice(-1)[0] : undefined;
   };
   // length :: [a] -> Int
   function length(xs) {
       return xs.length;
   };
   // map :: (a -> b) -> [a] -> [b]
   function map(f, xs) {
       return xs.map(f);
   };
   // 'The mapAccumL function behaves like a combination of map and foldl;
   // it applies a function to each element of a list, passing an accumulating
   // parameter from left to right, and returning a final value of this
   // accumulator together with the new list.' (See hoogle )
   // mapAccumL :: (acc -> x -> (acc, y)) -> acc -> [x] -> (acc, [y])
   function mapAccumL(f, acc, xs) {
       return xs.reduce(function (a, x) {
           var pair = f(a[0], x);
           return [pair[0], a[1].concat([pair[1]])];
       }, [acc, []]);
   };
   // show ::
   // (a -> String) f,  Num n =>
   // a -> maybe f -> maybe n -> String
   var show = JSON.stringify;
   // snd :: (a, b) -> b
   function snd(tpl) {
       return Array.isArray(tpl) ? tpl[1] : undefined;
   };
   // succ :: Int -> Int
   function succ(x) {
       return x + 1;
   };
   // unlines :: [String] -> String
   function unlines(xs) {
       return xs.join('\n');
   };
   // zipWith :: (a -> b -> c) -> [a] -> [b] -> [c]
   function zipWith(f, xs, ys) {
       var ny = ys.length;
       return (xs.length <= ny ? xs : xs.slice(0, ny))
           .map(function (x, i) {
               return f(x, ys[i]);
           });
   };
   // TEST ( n=5 and n=14 rows ) ---------------------------------------------
   return unlines(map(function (n) {
       return showFloyd(floyd(n)) + '\n';
   }, [5, 14]));

})();</lang>

Output:
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15

  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

ES6

Translation of: Haskell

(mapAccumL version)

<lang JavaScript>(() => {

   'use strict';
   // FLOYD's TRIANGLE -------------------------------------------------------
   // floyd :: Int -> Int
   const floyd = n => snd(mapAccumL(
       (start, row) => [start + row + 1, enumFromTo(start, start + row)],
       1, enumFromTo(0, n - 1)
   ));
   // showFloyd :: Int -> String
   const showFloyd = xss => {
       const ws = map(compose([succ, length, show]), last(xss));
       return unlines(
           map(xs => concat(zipWith(
                   (w, x) => justifyRight(w, ' ', show(x)), ws, xs
               )),
               xss
           )
       );
   };
   // GENERIC FUNCTIONS ------------------------------------------------------
   // compose :: [(a -> a)] -> (a -> a)
   const compose = fs => x => fs.reduceRight((a, f) => f(a), x);
   // concat :: a -> [a] | [String] -> String
   const concat = xs => {
       if (xs.length > 0) {
           const unit = typeof xs[0] === 'string' ?  : [];
           return unit.concat.apply(unit, xs);
       } else return [];
   };
   // enumFromTo :: Int -> Int -> [Int]
   const enumFromTo = (m, n) =>
       Array.from({
           length: Math.floor(n - m) + 1
       }, (_, i) => m + i);
   // justifyRight :: Int -> Char -> Text -> Text
   const justifyRight = (n, cFiller, strText) =>
       n > strText.length ? (
           (cFiller.repeat(n) + strText)
           .slice(-n)
       ) : strText;
   // last :: [a] -> a
   const last = xs => xs.length ? xs.slice(-1)[0] : undefined;
   // length :: [a] -> Int
   const length = xs => xs.length;
   // map :: (a -> b) -> [a] -> [b]
   const map = (f, xs) => xs.map(f)
   // 'The mapAccumL function behaves like a combination of map and foldl;
   // it applies a function to each element of a list, passing an accumulating
   // parameter from left to right, and returning a final value of this
   // accumulator together with the new list.' (See hoogle )
   // mapAccumL :: (acc -> x -> (acc, y)) -> acc -> [x] -> (acc, [y])
   const mapAccumL = (f, acc, xs) =>
       xs.reduce((a, x) => {
           const pair = f(a[0], x);
           return [pair[0], a[1].concat([pair[1]])];
       }, [acc, []]);
   // show ::
   // (a -> String) f,  Num n =>
   // a -> maybe f -> maybe n -> String
   const show = JSON.stringify;
   // snd :: (a, b) -> b
   const snd = tpl => Array.isArray(tpl) ? tpl[1] : undefined;
   // succ :: Int -> Int
   const succ = x => x + 1
   // unlines :: [String] -> String
   const unlines = xs => xs.join('\n');


   // zipWith :: (a -> b -> c) -> [a] -> [b] -> [c]
   const zipWith = (f, xs, ys) => {
       const ny = ys.length;
       return (xs.length <= ny ? xs : xs.slice(0, ny))
           .map((x, i) => f(x, ys[i]));
   };
   // TEST ( n=5 and n=14 rows ) ---------------------------------------------
   return unlines(map(n => showFloyd(floyd(n)) + '\n', [5, 14]))

})();</lang>

Output:
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15

  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

Spidermonkey

(Used TCL example as a starting point.)

<lang javascript>#!/usr/bin/env js

function main() {

   print('Floyd 5:');
   floyd(5);
   print('\nFloyd 14:');
   floyd(14);

}


function padLeft(s, w) {

   for (s = String(s); s.length < w; s = ' ' + s);
   return s;

}


function floyd(nRows) {

   var lowerLeft = nRows * (nRows - 1) / 2 + 1;
   var lowerRight = nRows * (nRows + 1) / 2;
   
   var colWidths = [];
   for (var col = lowerLeft; col <= lowerRight; col++) {
       colWidths.push(String(col).length);
   }
   var  num = 1;
   for (var row = 0; row < nRows; row++) {
       var line = [];
       for (var col = 0; col <= row; col++, num++) {
           line.push(padLeft(num, colWidths[col]));
       }
       print(line.join(' '));
   }

}

main();</lang>

Output:
 Floyd 5:
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 
 Floyd 14:
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

jq

<lang jq># floyd(n) creates an n-row floyd's triangle def floyd(n):

 def lpad(len): tostring | (((len - length) * " ")  + .);
 # Construct an array of widths.
 # Assuming N is the last integer on the last row (i.e. (n+1)*n/2),
 # the last row has n entries from (1+N-n) through N:
 def widths:
   ((n+1)*n/2) as $N
   | [range(1 + $N - n; $N + 1) | tostring | length];
 # emit line k assuming it starts with the integer "start"
 def line(start; k; widths):
   reduce range(start; start+k) as $i
     (""; . + ($i|lpad(widths[$i - start])) + " ");
 widths as $widths
 | (reduce range(0;n) as $row
     ( [0, ""];   # state: i, string
       (.[0] + 1) as $i | .[1] as $string
       | [ ($i + $row),
           ($string + "\n" + line($i; $row + 1; $widths )) ] )
   | .[1] ) ;</lang>

Task: <lang jq>(5,14) | "floyd(\(.)): \(floyd(.))\n"</lang>

Output:

<lang sh>$ jq -M -r -n -f floyds_triangle.jq > floyds_triangle.out floyd(5):

1 
2  3 
4  5  6 
7  8  9 10 

11 12 13 14 15

floyd(14):

1 
2  3 
4  5  6 
7  8  9 10 

11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 </lang>

Julia

<lang julia>function floydtriangle(rows)

   r = collect(1:div(rows *(rows + 1), 2))
   for i in 1:rows
       for j in 1:i
           print(rpad(lpad(popfirst!(r), j > 8 ? 3 : 2), j > 8 ? 4 : 3))
       end
       println()
   end

end

floydtriangle(5); println(); floydtriangle(14)

</lang>

Output:
 1      
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15

 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35 36
37 38 39 40 41 42 43 44  45
46 47 48 49 50 51 52 53  54  55
56 57 58 59 60 61 62 63  64  65  66
67 68 69 70 71 72 73 74  75  76  77  78 
79 80 81 82 83 84 85 86  87  88  89  90  91
92 93 94 95 96 97 98 99 100 101 102 103 104 105

Kotlin

Translation of: Java

<lang scala>fun main(args: Array<String>) = args.forEach { Triangle(it.toInt()) }

internal class Triangle(n: Int) {

   init {
       println("$n rows:")
       var printMe = 1
       var printed = 0
       var row = 1
       while (row <= n) {
           val cols = Math.ceil(Math.log10(n * (n - 1) / 2 + printed + 2.0)).toInt()
           print("%${cols}d ".format(printMe))
           if (++printed == row) { println(); row++; printed = 0 }
           printMe++
       }
   }

}</lang> Output as Java.

Lasso

This example does not show the output mentioned in the task description on this page (or a page linked to from here). There should only be one space between the numbers on the last row. Please ensure that it meets all task requirements and remove this message.
Note that phrases in task descriptions such as "print and display" and "print and show" for example, indicate that (reasonable length) output be a part of a language's solution.


<lang Lasso>define floyds_triangle(n::integer) => { local(out = array(array(1)),comp = array, num = 1) while(#out->size < #n) => { local(new = array) loop(#out->last->size + 1) => { #num++ #new->insert(#num) } #out->insert(#new) } local(pad = #out->last->last->asString->size) with line in #out do => { local(lineout = string) with i in #line do => { #i != #line->first ? #lineout->append(' ') #lineout->append((' '*(#pad - #i->asString->size))+#i) } #comp->insert(#lineout) } return #comp->join('\r') } floyds_triangle(5) '\r\r' floyds_triangle(14)</lang>

Output:
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15

  1
  2   3
  4   5   6
  7   8   9  10
 11  12  13  14  15
 16  17  18  19  20  21
 22  23  24  25  26  27  28
 29  30  31  32  33  34  35  36
 37  38  39  40  41  42  43  44  45
 46  47  48  49  50  51  52  53  54  55
 56  57  58  59  60  61  62  63  64  65  66
 67  68  69  70  71  72  73  74  75  76  77  78
 79  80  81  82  83  84  85  86  87  88  89  90  91
 92  93  94  95  96  97  98  99 100 101 102 103 104 105

Liberty BASIC

<lang lb>input "Number of rows needed:- "; rowsNeeded

dim colWidth(rowsNeeded) ' 5 rows implies 5 columns

for col=1 to rowsNeeded

   colWidth(col) = len(str$(col + rowsNeeded*(rowsNeeded-1)/2))

next

currentNumber =1

for row=1 to rowsNeeded

   for col=1 to row
       print right$( "  "+str$( currentNumber), colWidth(col)); " ";
       currentNumber = currentNumber + 1
   next
   print

next</lang>

Output:
Number of rows needed:- 5
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 

Number of rows needed:- 14
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 
16 17 18 19 20 21 
22 23 24 25 26 27 28 
29 30 31 32 33 34 35 36 
37 38 39 40 41 42 43 44  45 
46 47 48 49 50 51 52 53  54  55 
56 57 58 59 60 61 62 63  64  65  66 
67 68 69 70 71 72 73 74  75  76  77  78 
79 80 81 82 83 84 85 86  87  88  89  90  91 
92 93 94 95 96 97 98 99 100 101 102 103 104 105 

Lua

<lang lua>function print_floyd(rows) local c = 1 local h = rows*(rows-1)/2 for i=1,rows do local s = "" for j=1,i do for k=1, #tostring(h+j)-#tostring(c) do s = s .. " " end if j ~= 1 then s = s .. " " end s = s .. tostring(c) c = c + 1 end print(s) end end

print_floyd(5) print_floyd(14)</lang>

Output:

 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35 36
37 38 39 40 41 42 43 44  45
46 47 48 49 50 51 52 53  54  55
56 57 58 59 60 61 62 63  64  65  66
67 68 69 70 71 72 73 74  75  76  77  78
79 80 81 82 83 84 85 86  87  88  89  90  91
92 93 94 95 96 97 98 99 100 101 102 103 104 105

Maple

<lang maple>floyd := proc(rows) local num, numRows, numInRow, i, digits; digits := Array([]); for i to 2 do num := 1; numRows := 1; numInRow := 1; while numRows <= rows do if i = 2 then printf(cat("%", digits[numInRow], "a "), num); end if; num := num + 1; if i = 1 and numRows = rows then digits(numInRow) := StringTools[Length](convert(num-1, string)); end if; if numInRow >= numRows then if i = 2 then printf("\n"); end if; numInRow := 1; numRows := numRows + 1; else numInRow := numInRow +1; end if; end do; end do; return NULL; end proc:

floyd(5); floyd(14);</lang>

Output:
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 
16 17 18 19 20 21 
22 23 24 25 26 27 28 
29 30 31 32 33 34 35 36 
37 38 39 40 41 42 43 44  45 
46 47 48 49 50 51 52 53  54  55 
56 57 58 59 60 61 62 63  64  65  66 
67 68 69 70 71 72 73 74  75  76  77  78 
79 80 81 82 83 84 85 86  87  88  89  90  91 
92 93 94 95 96 97 98 99 100 101 102 103 104 105 

Mathematica / Wolfram Language

<lang Mathematica> f=Function[n, Most/@(Range@@@Partition[FindSequenceFunction[{1,2,4,7,11}]/@Range[n+1],2,1])] TableForm[f@5,TableAlignments->Right,TableSpacing->{1,1}] TableForm[f@14,TableAlignments->Right,TableSpacing->{1,1}] </lang> Output:

  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15

  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

MATLAB / Octave

<lang Matlab>function floyds_triangle(n)

 s = 1;
 for k = 1 : n
   disp(s : s + k - 1)
   s = s + k;
 end</lang>
Output:
octave:22> floyds_triangle(5)
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15

Modula-2

<lang modula2>MODULE FloydTriangle; FROM FormatString IMPORT FormatString; FROM Terminal IMPORT WriteString,WriteLn,ReadChar;

PROCEDURE WriteInt(n : INTEGER); VAR buf : ARRAY[0..9] OF CHAR; BEGIN

   FormatString("%4i", buf, n);
   WriteString(buf)

END WriteInt;

PROCEDURE Print(r : INTEGER); VAR n,i,limit : INTEGER; BEGIN

   IF r<0 THEN RETURN END;
   n := 1;
   limit := 1;
   WHILE r#0 DO
       FOR i:=1 TO limit DO
           WriteInt(n);
           INC(n)
       END;
       WriteLn;
       DEC(r);
       INC(limit)
   END

END Print;

BEGIN

   Print(5);
   WriteLn;
   Print(14);
   ReadChar

END FloydTriangle.</lang>

Output:
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15

  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

NetRexx

Both REXX versions lend themselves very well to conversion into NetRexx programs with few changes.

Version 1

Translation of: REXX

<lang NetRexx>/* NetRexx */ options replace format comments java crossref symbols binary /* REXX ***************************************************************

  • 12.07.2012 Walter Pachl - translated from Python
                                                                                                                                            • /

Parse Arg rowcount . if rowcount.length() == 0 then rowcount = 1 say 'Rows:' rowcount say col = 0 len = Rexx ll = -- last line of triangle Loop j = rowcount * (rowcount - 1) / 2 + 1 to rowcount * (rowcount + 1) / 2

 col = col + 1                       -- column number
 ll = ll j                           -- build last line
 len[col] = j.length()               -- remember length of column
 End j

Loop i = 1 To rowcount - 1 -- now do and output the rest

 ol = 
 col = 0
 Loop j = i * (i - 1) / 2 + 1 to i * (i + 1) / 2 -- elements of line i
   col = col + 1
   ol=ol j.right(len[col])           -- element in proper length
   end
 Say ol                              -- output ith line
 end i

Say ll -- output last line </lang> Output:

Rows: 5 
 
  1 
  2  3 
  4  5  6 
  7  8  9 10 
 11 12 13 14 15 

Rows: 14 
 
  1 
  2  3 
  4  5  6 
  7  8  9 10 
 11 12 13 14 15 
 16 17 18 19 20 21 
 22 23 24 25 26 27 28 
 29 30 31 32 33 34 35 36 
 37 38 39 40 41 42 43 44  45 
 46 47 48 49 50 51 52 53  54  55 
 56 57 58 59 60 61 62 63  64  65  66 
 67 68 69 70 71 72 73 74  75  76  77  78 
 79 80 81 82 83 84 85 86  87  88  89  90  91 
 92 93 94 95 96 97 98 99 100 101 102 103 104 105 

Version 2

Translation of: REXX

<lang NetRexx>/* NetRexx */ options replace format comments java crossref symbols binary /*REXX program constructs & displays Floyd's triangle for any number of rows.*/ parse arg numRows . if numRows == then numRows = 1 -- assume 1 row if not given maxVal = numRows * (numRows + 1) % 2 -- calculate the max value. say 'displaying a' numRows "row Floyd's triangle:" say digit = 1 loop row = 1 for numRows

 col = 0
 output = 
 loop digit = digit for row
   col = col + 1
   colMaxDigit = maxVal - numRows + col
   output = output Rexx(digit).right(colMaxDigit.length())
   end digit
 say output
 end row

</lang>

Output:

displaying a 5 row Floyd's triangle: 
 
  1 
  2  3 
  4  5  6 
  7  8  9 10 
 11 12 13 14 15
  
displaying a 14 row Floyd's triangle: 
 
  1 
  2  3 
  4  5  6 
  7  8  9 10 
 11 12 13 14 15 
 16 17 18 19 20 21 
 22 23 24 25 26 27 28 
 29 30 31 32 33 34 35 36 
 37 38 39 40 41 42 43 44  45 
 46 47 48 49 50 51 52 53  54  55 
 56 57 58 59 60 61 62 63  64  65  66 
 67 68 69 70 71 72 73 74  75  76  77  78 
 79 80 81 82 83 84 85 86  87  88  89  90  91 
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

Nim

Translation of: Python

<lang nim>import strutils

proc floyd(rowcount = 5): seq[seq[int]] =

 result = @[@[1]]
 while result.len < rowcount:
   let n = result[result.high][result.high] + 1
   var row = newSeq[int]()
   for i in n .. n + result[result.high].len:
     row.add i
   result.add row

proc pfloyd(rows: seq[seq[int]]) =

 var colspace = newSeq[int]()
 for n in rows[rows.high]: colspace.add(($n).len)
 for row in rows:
   for i, x in row:
     stdout.write align($x, colspace[i])," "
   echo ""

for i in [5, 14]:

 pfloyd(floyd(i))
 echo ""</lang>

Output:

 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 

 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 
16 17 18 19 20 21 
22 23 24 25 26 27 28 
29 30 31 32 33 34 35 36 
37 38 39 40 41 42 43 44  45 
46 47 48 49 50 51 52 53  54  55 
56 57 58 59 60 61 62 63  64  65  66 
67 68 69 70 71 72 73 74  75  76  77  78 
79 80 81 82 83 84 85 86  87  88  89  90  91 
92 93 94 95 96 97 98 99 100 101 102 103 104 105 

OCaml

<lang ocaml>let ( |> ) f g x = g (f x) let rec last = function x::[] -> x | _::tl -> last tl | [] -> raise Not_found let rec list_map2 f l1 l2 =

 match (l1, l2) with
 | ([], _) | (_, []) -> []
 | (x::xs, y::ys) -> (f x y) :: list_map2 f xs ys

let floyd n =

 let rec aux acc cur len i j =
   if (List.length acc) = n then (List.rev acc) else
     if j = len
     then aux ((List.rev cur)::acc) [] (succ len) i 0
     else aux acc (i::cur) len (succ i) (succ j)
 in
 aux [] [] 1 1 0

let print_floyd f =

 let lens = List.map (string_of_int |> String.length) (last f) in
 List.iter (fun row ->
   print_endline (
     String.concat " " (
       list_map2 (Printf.sprintf "%*d") lens row))
 ) f

let () =

 print_floyd (floyd (int_of_string Sys.argv.(1)))</lang>

OxygenBasic

This example does not show the output mentioned in the task description on this page (or a page linked to from here). Please ensure that it meets all task requirements and remove this message.
Note that phrases in task descriptions such as "print and display" and "print and show" for example, indicate that (reasonable length) output be a part of a language's solution.


<lang oxygenbasic> function Floyd(sys n) as string sys i,t for i=1 to n

 t+=i

next string s=str t sys le=1+len s string cr=chr(13,10) sys lc=len cr string buf=space(le*t+n*lc) sys j,o,p=1 t=0 for i=1 to n

 for j=1 to i
   t++
   s=str t
   o=le-len(s)-1 'right justify
   mid buf,p+o,str t
   p+=le
 next
 mid buf,p,cr
 p+=lc

next return left buf,p-1 end function

putfile "s.txt",Floyd(5)+floyd(14) </lang>

PARI/GP

<lang parigp>{floyd(m)=my(lastrow_a,lastrow_e,lastrow_len=m,fl,idx);

    \\ +++  fl is a vector of fieldlengths in the last row 
lastrow_e=m*(m+1)/2;lastrow_a=lastrow_e+1-m;
   fl=vector(lastrow_len);
   for(k=1,m,fl[k] = 1 + #Str(k-1+lastrow_a) );
\\ 
idx=0;
for(i=1,m, 
     for(j=1,i,
           idx++; 
           printf(Str("%" fl[j] "d"),idx)
        );
      print()
    );
return();}

floyd(5) floyd(14) </lang>

Output:
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

Pascal

Works with: Free_Pascal

<lang pascal>Program FloydDemo (input, output);

function digits(number: integer): integer;

 begin
   digits := trunc(ln(number) / ln(10)) + 1;
 end;

procedure floyd1 (numberOfLines: integer); { variant with repeat .. until loop }

 var
   i, j, numbersInLine, startOfLastlLine: integer;

 begin
   startOfLastlLine := (numberOfLines - 1) * numberOfLines div 2 + 1;
   i := 1;
   j := 1;
   numbersInLine := 1;
   repeat
     repeat
       write(i: digits(startOfLastlLine - 1 + j), ' ');
       inc(i);

inc(j);

     until (j > numbersInLine);
     writeln;
     j := 1;
     inc(numbersInLine);
   until (numbersInLine > numberOfLines);
 end;

procedure floyd2 (numberOfLines: integer); { Variant with for .. do loop }

 var
   i, j, numbersInLine, startOfLastlLine: integer;

 begin
   startOfLastlLine := (numberOfLines - 1) * numberOfLines div 2 + 1;
   i := 1;
   for numbersInLine := 1 to numberOfLines do
   begin
     for j := 1 to numbersInLine do
     begin
       write(i: digits(startOfLastlLine - 1 + j), ' ');
       inc(i);
     end;
     writeln;
   end;
 end;

begin

 writeln ('*** Floyd 5 ***');
 floyd1(5);
 writeln;
 writeln ('*** Floyd 14 ***');
 floyd2(14);

end.</lang> Output:

% ./Floyd
*** Floyd 5 ***
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 

*** Floyd 14 ***
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 
16 17 18 19 20 21 
22 23 24 25 26 27 28 
29 30 31 32 33 34 35 36 
37 38 39 40 41 42 43 44  45 
46 47 48 49 50 51 52 53  54  55 
56 57 58 59 60 61 62 63  64  65  66 
67 68 69 70 71 72 73 74  75  76  77  78 
79 80 81 82 83 84 85 86  87  88  89  90  91 
92 93 94 95 96 97 98 99 100 101 102 103 104 105 

Perl

Translation of: NetRexx

<lang perl>#!/usr/bin/env perl use strict; use warnings;

sub displayFloydTriangle {

 my $numRows = shift;
 print "\ndisplaying a $numRows row Floyd's triangle:\n\n";
 my $maxVal = int($numRows * ($numRows + 1) / 2); # calculate the max value.
 my $digit = 0;
 foreach my $row (1 .. $numRows) {
   my $col = 0;
   my $output = ;
   foreach (1 .. $row) {
     ++$digit;
     ++$col;
     my $colMaxDigit = $maxVal - $numRows + $col;
     $output .= sprintf " %*d", length($colMaxDigit), $digit;
   }
   print "$output\n";
 }
 return;

}

  1. ==== Main ================================================

my @counts; @counts = @ARGV; @counts = (5, 14) unless @ARGV;

foreach my $count (@counts) {

 displayFloydTriangle($count);

}

0; __END__ </lang> Output:

displaying a 5 row Floyd's triangle:

  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15

displaying a 14 row Floyd's triangle:

  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

Phix

with javascript_semantics
procedure Floyds_triangle(integer n)
    sequence widths = repeat(0,n)
    integer k = (n * (n-1))/2
    for i=1 to n do
        widths[i] = sprintf("%%%dd",length(sprintf("%d",i+k))+1)
    end for
    k = 1
    for i=1 to n do
        for j=1 to i do
            printf(1,widths[j],k)
            k += 1
        end for
        printf(1,"\n")
    end for
end procedure
Floyds_triangle(5)
Floyds_triangle(14)
Output:
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

PHP

<lang php> <?php floyds_triangle(5); floyds_triangle(14);

function floyds_triangle($n) {

   echo "n = " . $n . "\r\n";
   for($r = 1, $i = 1, $c = 0; $r <= $n; $i++) {
       $cols = ceil(log10($n*($n-1)/2 + $c + 2));
       printf("%".$cols."d ", $i);
       if(++$c == $r) {
           echo "\r\n";
           $r++;
           $c = 0;
       }
   }

?> </lang>

Output:
 
n = 5
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 
n = 14
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 
16 17 18 19 20 21 
22 23 24 25 26 27 28 
29 30 31 32 33 34 35 36 
37 38 39 40 41 42 43 44  45 
46 47 48 49 50 51 52 53  54  55 
56 57 58 59 60 61 62 63  64  65  66 
67 68 69 70 71 72 73 74  75  76  77  78 
79 80 81 82 83 84 85 86  87  88  89  90  91 
92 93 94 95 96 97 98 99 100 101 102 103 104 105 

PicoLisp

Calculate widths relative to lower left corner

<lang PicoLisp>(de floyd (N)

  (let LLC (/ (* N (dec N)) 2)
     (for R N
        (for C R
           (prin
              (align
                 (length (+ LLC C))
                 (+ C (/ (* R (dec R)) 2)) ) )
           (if (= C R) (prinl) (space)) ) ) ) )</lang>

Pre-calculate all rows, and take format from last one

<lang PicoLisp>(de floyd (N)

  (let
     (Rows
        (make
           (for ((I . L) (range 1 (/ (* N (inc N)) 2))  L)
              (link (cut I 'L)) ) )
        Fmt (mapcar length (last Rows)) )
     (map inc (cdr Fmt))
     (for R Rows
        (apply tab R Fmt) ) ) )</lang>

Output in both cases:

: (floyd 5)
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15

: (floyd 14)
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35 36
37 38 39 40 41 42 43 44  45
46 47 48 49 50 51 52 53  54  55
56 57 58 59 60 61 62 63  64  65  66
67 68 69 70 71 72 73 74  75  76  77  78
79 80 81 82 83 84 85 86  87  88  89  90  91
92 93 94 95 96 97 98 99 100 101 102 103 104 105

PL/I

<lang pli>(fofl, size): floyd: procedure options (main); /* Floyd's Triangle. Wiki 12 July 2012 */

  declare (i, m, n) fixed (10), (j, k, w, nr) fixed binary;
  put list ('How many rows do you want?');
  get list (nr);   /* the number of rows   */
  n = nr*(nr+1)/2; /* the total number of values */
  j,k = 1; m = n - nr + 1;
  do i = 1 to n;
     put edit (i) ( x(1), f(length(trim(m))) );
     if k > 1 then do; k = k - 1; m = m + 1; end;
     else do; k,j = j + 1; m = n - nr + 1; put skip; end;
  end;

end floyd;</lang>

Output:
How many rows do you want?
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15

How many rows do you want? 
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

Final row for n=45:
 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035

Prolog

Works with SWI-Prolog version 6.5.3 <lang Prolog>floyd(N) :- forall(between(1, N, I), ( forall(between(1,I, J), ( Last is N * (N-1)/2+J, V is I * (I-1) /2 + J, get_column(Last, C), sformat(AR, '~~t~~w~~~w| ', [C]), sformat(AF, AR, [V]), writef(AF))), nl)).

get_column(Last, C) :- name(Last, N1), length(N1,C). </lang> Output :

 ?- floyd(5).
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 
true.

 ?- floyd(14).
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 
16 17 18 19 20 21 
22 23 24 25 26 27 28 
29 30 31 32 33 34 35 36 
37 38 39 40 41 42 43 44  45 
46 47 48 49 50 51 52 53  54  55 
56 57 58 59 60 61 62 63  64  65  66 
67 68 69 70 71 72 73 74  75  76  77  78 
79 80 81 82 83 84 85 86  87  88  89  90  91 
92 93 94 95 96 97 98 99 100 101 102 103 104 105 
true.

PureBasic

<lang PureBasic>Procedure.i sumTo(n)

 Protected r,i
 For i=1 To n 
   r+i
 Next 
 ProcedureReturn r.i

EndProcedure

[1]
array rsA(n)... string-lengths of the numbers
in the bottom row
[2]
sumTo(i-1)+1 to sumTo(i)
          ; 11 12 13 14 15
 ; here k is the column-index for array rsA(k)

Procedure.s FloydsTriangle(n)

 Protected r.s,s.s,t.s,i,j,k
 ; [1]
 Dim rsA(n)
 i=0
 For j=sumTo(n-1)+1 To sumTo(n)
   i+1
   rsA(i)=Len(Str(j))
 Next
 ; [2]
 For i=1 To n 
   t.s="":k=0
   For j=sumTo(i-1)+1 To sumTo(i)
     k+1:t.s+RSet(Str(j),rsA(k)," ")+" "
   Next 
   r.s+RTrim(t.s)+Chr(13)+Chr(10)
 Next 
 r.s=Left(r.s,Len(r.s)-2)
 ProcedureReturn r.s

EndProcedure

If OpenConsole()

 n=5
 r.s=FloydsTriangle(n)
 PrintN(r.s)
 
 n=14
 r.s=FloydsTriangle(n)
 PrintN(r.s)
 
 Print(#crlf$ + #crlf$ + "Press ENTER to exit"): Input()
 CloseConsole()

EndIf</lang>

Sample Output

 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35 36
37 38 39 40 41 42 43 44  45
46 47 48 49 50 51 52 53  54  55
56 57 58 59 60 61 62 63  64  65  66
67 68 69 70 71 72 73 74  75  76  77  78
79 80 81 82 83 84 85 86  87  88  89  90  91
92 93 94 95 96 97 98 99 100 101 102 103 104 105

Python

Procedural

<lang python>>>> def floyd(rowcount=5): rows = 1 while len(rows) < rowcount: n = rows[-1][-1] + 1 rows.append(list(range(n, n + len(rows[-1]) + 1))) return rows

>>> floyd() [[1], [2, 3], [4, 5, 6], [7, 8, 9, 10], [11, 12, 13, 14, 15]] >>> def pfloyd(rows=[[1], [2, 3], [4, 5, 6], [7, 8, 9, 10]]): colspace = [len(str(n)) for n in rows[-1]] for row in rows: print( ' '.join('%*i' % space_n for space_n in zip(colspace, row)))


>>> pfloyd() 1 2 3 4 5 6 7 8 9 10 >>> pfloyd(floyd(5))

1
2  3
4  5  6
7  8  9 10

11 12 13 14 15 >>> pfloyd(floyd(14))

1
2  3
4  5  6
7  8  9 10

11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 >>> </lang>

Functional

Using the mathematical formula for each row directly, either in a list comprehension: <lang python>def floyd(rowcount=5):

   return [list(range(i * (i - 1) // 2 + 1, i * (i + 1) // 2 + 1))
           for i in range(1, rowcount + 1)]</lang>

or in terms of concatMap:

Works with: Python version 3

<lang python>Floyd triangle in terms of concatMap

from itertools import chain


  1. floyd :: Int -> Int

def floyd(n):

   n rows of a Floyd triangle.
   def f(i):
       return [
           enumFromTo(i * pred(i) // 2 + 1)(
               i * succ(i) // 2
           )
       ]
   return concatMap(f)(enumFromTo(1)(n))


  1. main :: IO ()

def main():

   Test
   print(unlines(
       map(str, floyd(5))
   ))


  1. GENERIC FUNCTIONS ---------------------------------------


  1. enumFromTo :: (Int, Int) -> [Int]

def enumFromTo(m):

   Integer enumeration from m to n.
   return lambda n: list(range(m, 1 + n))


  1. concatMap :: (a -> [b]) -> [a] -> [b]

def concatMap(f):

   Concatenated list over which a function has been mapped.
      The list monad can be derived by using a function f which
      wraps its output in a list,
      (using an empty list to represent computational failure).
   return lambda xs: list(
       chain.from_iterable(
           map(f, xs)
       )
   )


  1. pred :: Enum a => a -> a

def pred(x):

   The predecessor of a value. For numeric types, (- 1).
   return x - 1 if isinstance(x, int) else (
       chr(ord(x) - 1)
   )


  1. succ :: Enum a => a -> a

def succ(x):

   The successor of a value. For numeric types, (1 +).
   return 1 + x if isinstance(x, int) else (
       chr(1 + ord(x))
   )


  1. unlines :: [String] -> String

def unlines(xs):

   A single string derived by the intercalation
      of a list of strings with the newline character.
   return '\n'.join(xs)


if __name__ == '__main__':

   main()</lang>

Or alternatively, defining just the relationship between successive terms:

Works with: Python version 3

<lang python>Floyd triangle in terms of iterate(f)(x)

from itertools import islice


  1. floyd :: Int -> Int

def floyd(n):

   n rows of a Floyd triangle.
   return take(n)(iterate(nextFloyd)([1]))


  1. nextFloyd :: [Int] -> [Int]

def nextFloyd(xs):

   A Floyd triangle row derived from
      the preceding row.
   n = succ(len(xs))
   return [1] if n < 2 else (
       enumFromTo(succ(n * pred(n) // 2))(
           n * succ(n) // 2
       )
   )


  1. showFloyd :: Int -> String

def showFloyd(xs):

   A stringification of Floyd triangle rows.
   return unlines(str(x) for x in xs)


  1. main :: IO ()

def main():

   Test
   print(showFloyd(
       floyd(5)
   ))


  1. GENERIC ABSTRACTIONS ------------------------------------
  1. enumFromTo :: (Int, Int) -> [Int]

def enumFromTo(m):

   Integer enumeration from m to n.
   return lambda n: list(range(m, 1 + n))


  1. iterate :: (a -> a) -> a -> Gen [a]

def iterate(f):

   An infinite list of repeated applications of f to x.
   def go(x):
       v = x
       while True:
           yield v
           v = f(v)
   return lambda x: go(x)


  1. pred :: Enum a => a -> a

def pred(x):

   The predecessor of a value. For numeric types, (- 1).
   return x - 1 if isinstance(x, int) else (
       chr(ord(x) - 1)
   )


  1. succ :: Enum a => a -> a

def succ(x):

   The successor of a value. For numeric types, (1 +).
   return 1 + x if isinstance(x, int) else (
       chr(1 + ord(x))
   )


  1. take :: Int -> [a] -> [a]
  2. take :: Int -> String -> String

def take(n):

   The prefix of xs of length n,
      or xs itself if n > length xs.
   return lambda xs: (
       xs[0:n]
       if isinstance(xs, list)
       else list(islice(xs, n))
   )


  1. unlines :: [String] -> String

def unlines(xs):

   A single string derived by the intercalation
      of a list of strings with the newline character.
   return '\n'.join(xs)


  1. MAIN ----------------------------------------------------

if __name__ == '__main__':

   main()</lang>
Output:
[1]
[2, 3]
[4, 5, 6]
[7, 8, 9, 10]
[11, 12, 13, 14, 15]

q

<lang q> floyd:{n:1+ til sum 1+til x;

      t:d:0;
      while[1+x-:1;0N!(t+:1)#(d+:t)_n]}

floyd2:{n:1+ til sum 1+til x;

       t:d:0;
       while[1+x-:1;1 (" " sv string each (t+:1)#(d+:t)_n),"\n"]}

//The latter function 'floyd2' includes logic to remove the leading "," before "1" in the first row.

floyd[5] floyd2[14]</lang>

Output:
,1
2 3
4 5 6
7 8 9 10
11 12 13 14 15

1
2 3
4 5 6
7 8 9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35 36
37 38 39 40 41 42 43 44 45
46 47 48 49 50 51 52 53 54 55
56 57 58 59 60 61 62 63 64 65 66
67 68 69 70 71 72 73 74 75 76 77 78
79 80 81 82 83 84 85 86 87 88 89 90 91
92 93 94 95 96 97 98 99 100 101 102 103 104 105

Quackery

<lang Quackery> [ dup 1+ * 2 / ] is triangulared ( n --> n )

 [ number$ tuck size - 
   times sp echo$ ]     is rightecho    ( n n -->   )
 [ dup triangulared
   number$ size 1+
   0 rot times
     [ i^ 1+ times
       [ 1+ 2dup 
         rightecho ]
       cr ]
   2drop ]              is floyd        (   n -->   )
  5 floyd
 cr 
 14 floyd</lang>
Output:
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15

   1
   2   3
   4   5   6
   7   8   9  10
  11  12  13  14  15
  16  17  18  19  20  21
  22  23  24  25  26  27  28
  29  30  31  32  33  34  35  36
  37  38  39  40  41  42  43  44  45
  46  47  48  49  50  51  52  53  54  55
  56  57  58  59  60  61  62  63  64  65  66
  67  68  69  70  71  72  73  74  75  76  77  78
  79  80  81  82  83  84  85  86  87  88  89  90  91
  92  93  94  95  96  97  98  99 100 101 102 103 104 105

R

If it weren't for the printing requirements, we could do this in one line. <lang rsplus>Floyd <- function(n) {

 #The first argument of the seq call is a well-known formula for triangle numbers.
 out <- t(sapply(seq_len(n), function(i) c(seq(to = 0.5 * (i * (i + 1)), by = 1, length.out = i), rep(NA, times = n - i))))
 dimnames(out) <- list(rep("", times = nrow(out)), rep("", times = ncol(out)))
 print(out, na.print = "")

} Floyd(5) Floyd(14)</lang>

Output:
               
  1            
  2  3         
  4  5  6      
  7  8  9 10   
 11 12 13 14 15
                                                
  1                                             
  2  3                                          
  4  5  6                                       
  7  8  9 10                                    
 11 12 13 14 15                                 
 16 17 18 19 20 21                              
 22 23 24 25 26 27 28                           
 29 30 31 32 33 34 35 36                        
 37 38 39 40 41 42 43 44  45                    
 46 47 48 49 50 51 52 53  54  55                
 56 57 58 59 60 61 62 63  64  65  66            
 67 68 69 70 71 72 73 74  75  76  77  78        
 79 80 81 82 83 84 85 86  87  88  89  90  91    
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

Racket

<lang racket>

  1. lang racket

(require math)

(define (tri n)

 (if (zero? n) 0 (triangle-number n)))

(define (floyd n)

 (define (width x) (string-length (~a x)))
 (define (~n x c) (~a x 
                      #:width (width (+ (tri (- n 1)) 1 c))
                      #:align 'right #:left-pad-string " "))
 (for ([r n])
   (for ([c (+ r 1)]) 
     (display (~a (~n (+ (tri r) 1 c) c) " ")))
   (newline)))

(floyd 5) (floyd 14) </lang> Output:

 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 
16 17 18 19 20 21 
22 23 24 25 26 27 28 
29 30 31 32 33 34 35 36 
37 38 39 40 41 42 43 44  45 
46 47 48 49 50 51 52 53  54  55 
56 57 58 59 60 61 62 63  64  65  66 
67 68 69 70 71 72 73 74  75  76  77  78 
79 80 81 82 83 84 85 86  87  88  89  90  91 
92 93 94 95 96 97 98 99 100 101 102 103 104 105 

Raku

(formerly Perl 6) Here's two ways of doing it. <lang perl6>constant @floyd1 = (1..*).rotor(1..*); constant @floyd2 = gather for 1..* -> $s { take [++$ xx $s] }

sub format-rows(@f) {

   my @table;
   my @formats = @f[@f-1].map: {"%{.chars}s"}
   for @f -> @row {
       @table.push: (@row Z @formats).map: -> ($i, $f) { $i.fmt($f) }
   }
   join "\n", @table;

}

say format-rows(@floyd1[^5]); say ; say format-rows(@floyd2[^14]);</lang>

Output:
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15
 
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 
16 17 18 19 20 21 
22 23 24 25 26 27 28 
29 30 31 32 33 34 35 36 
37 38 39 40 41 42 43 44  45 
46 47 48 49 50 51 52 53  54  55 
56 57 58 59 60 61 62 63  64  65  66 
67 68 69 70 71 72 73 74  75  76  77  78 
79 80 81 82 83 84 85 86  87  88  89  90  91 
92 93 94 95 96 97 98 99 100 101 102 103 104 105

REXX

version 1

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

  • Parse Arg rowcount
  • 12.07.2012 Walter Pachl - translated from Python
                                                                                                                                            • /

Parse Arg rowcount col=0 ll= /* last line of triangle */ Do j=rowcount*(rowcount-1)/2+1 to rowcount*(rowcount+1)/2

 col=col+1                         /* column number                 */ 
 ll=ll j                           /* build last line               */ 
 len.col=length(j)                 /* remember length of column     */ 
 End                                                                   

Do i=1 To rowcount-1 /* now do and output the rest */

 ol=                                                                 
 col=0                                                                 
 Do j=i*(i-1)/2+1 to i*(i+1)/2     /* elements of line i            */ 
   col=col+1                                                           
   ol=ol right(j,len.col)          /* element in proper length      */ 
   end                                                                 
 Say ol                            /* output ith line               */ 
 end                                                                   

Say ll /* output last line */ </lang> Output:

n=5
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15 

n=14  
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105 

version 2, simple formula

This REXX version uses a simple formula to calculate the maximum value (triangle element) displayed. <lang rexx>/*REXX program constructs & displays Floyd's triangle for any number of specified rows.*/ parse arg N .; if N== | N=="," then N= 5 /*Not specified? Then use the default.*/ mx= N * (N+1) % 2 - N /*calculate the maximum of any value. */ say 'displaying a ' N " row Floyd's triangle:" /*show the header for Floyd's triangle.*/ say /*display a blank line below the title.*/

  1. =1; do r=1 for N; i= 0; _= /*construct Floyd's triangle row by row*/
          do #=#  for r;           i= i + 1     /*start to construct a row of triangle.*/
          _= _ right(#, length( mx+i ) )        /*build a row of the Floyd's triangle. */
          end   /*#*/                           /*calculate the max length on the fly. */
       say substr(_, 2)                         /*remove 1st leading blank in the line.*/
       end      /*r*/                           /*stick a fork in it,  we're all done. */</lang>
output   when using the default input:
displaying a  5  row Floyd's triangle:

 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
output   when using the default input of:   14
displaying a  14  row Floyd's triangle:

 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35 36
37 38 39 40 41 42 43 44  45
46 47 48 49 50 51 52 53  54  55
56 57 58 59 60 61 62 63  64  65  66
67 68 69 70 71 72 73 74  75  76  77  78
79 80 81 82 83 84 85 86  87  88  89  90  91
92 93 94 95 96 97 98 99 100 101 102 103 104 105
output   (only showing the last row) when using the input of:   45
  ··· 44 rows not shown ··· 
991  992  993  994  995  996  997  998  999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035

version 3, hexadecimal

<lang rexx>/*REXX program constructs & displays Floyd's triangle for any number of rows in base 16.*/ parse arg N .; if N== | N=="," then N=6 /*Not specified? Then use the default.*/ mx=N * (N+1) % 2 - N /*calculate maximum value of any value.*/ say 'displaying a ' N " row Floyd's triangle in base 16:" /*show triangle header.*/ say

  1. =1; do r=1 for N; i=0; _= /*construct Floyd's triangle row by row*/
         do #=#  for r;     i=i+1               /*start to construct a row of triangle.*/
         _=_ right( d2x(#), length( d2x(mx+i))) /*build a row of the Floyd's triangle. */
         end   /*#*/
     say substr(_, 2)                           /*remove 1st leading blank in the line.*/
     end       /*r*/                            /*stick a fork in it,  we're all done. */</lang>
output   when using the default input:
displaying a  6  row Floyd's triangle in base 16:

 1
 2  3
 4  5  6
 7  8  9  A
 B  C  D  E  F
10 11 12 13 14 15
output   when using the input of:   23
displaying a  23  row Floyd's triangle in base 16:

 1
 2  3
 4  5   6
 7  8   9   A
 B  C   D   E   F
10 11  12  13  14  15
16 17  18  19  1A  1B  1C
1D 1E  1F  20  21  22  23  24
25 26  27  28  29  2A  2B  2C  2D
2E 2F  30  31  32  33  34  35  36  37
38 39  3A  3B  3C  3D  3E  3F  40  41  42
43 44  45  46  47  48  49  4A  4B  4C  4D  4E
4F 50  51  52  53  54  55  56  57  58  59  5A  5B
5C 5D  5E  5F  60  61  62  63  64  65  66  67  68  69
6A 6B  6C  6D  6E  6F  70  71  72  73  74  75  76  77  78
79 7A  7B  7C  7D  7E  7F  80  81  82  83  84  85  86  87  88
89 8A  8B  8C  8D  8E  8F  90  91  92  93  94  95  96  97  98  99
9A 9B  9C  9D  9E  9F  A0  A1  A2  A3  A4  A5  A6  A7  A8  A9  AA  AB
AC AD  AE  AF  B0  B1  B2  B3  B4  B5  B6  B7  B8  B9  BA  BB  BC  BD  BE
BF C0  C1  C2  C3  C4  C5  C6  C7  C8  C9  CA  CB  CC  CD  CE  CF  D0  D1  D2
D3 D4  D5  D6  D7  D8  D9  DA  DB  DC  DD  DE  DF  E0  E1  E2  E3  E4  E5  E6  E7
E8 E9  EA  EB  EC  ED  EE  EF  F0  F1  F2  F3  F4  F5  F6  F7  F8  F9  FA  FB  FC  FD
FE FF 100 101 102 103 104 105 106 107 108 109 10A 10B 10C 10D 10E 10F 110 111 112 113 114

version 4, up to base 90

This REXX version could be extended to even higher bases, all that is needed is to append more viewable characters to express "higher" numerals   ("digits" in base X).

This version of the base function has some boilerplate for signed numbers and various error checking. <lang rexx>/*REXX program constructs/shows Floyd's triangle for any number of rows in any base ≤90.*/ parse arg N radx . /*obtain optional arguments from the CL*/ if N== | N=="," then N= 5 /*Not specified? Then use the default.*/ if radx== | radx=="," then radx=10 /* " " " " " " */ mx=N * (N+1) % 2 - N /*calculate maximum value of any value.*/ say 'displaying a ' N " row Floyd's triangle in base" radx':' /*display the header.*/ say

  1. =1; do r=1 for N; i=0; _= /*construct Floyd's triangle row by row*/
        do #=#  for r;    i=i+1                 /*start to construct a row of triangle.*/
        _=_ right(base(#, radx),  length( base(mx+i, radx) ) )    /*build triangle row.*/
        end   /*#*/
     say substr(_, 2)                           /*remove 1st leading blank in the line,*/
     end      /*r*/                             /* [↑]   introduced by first abutment. */

exit /*stick a fork in it, we're all done. */ /*──────────────────────────────────────────────────────────────────────────────────────*/ base: procedure; parse arg x 1 ox,toB,inB /*obtain number, toBase, inBase. */

     @abc= 'abcdefghijklmnopqrstuvwxyz'               /*lowercase Latin alphabet.      */
     @abcU=@abc;        upper @abcU                   /*go whole hog and extend 'em.   */
     @@@= '0123456789'@abc || @abcU                   /*prefix 'em with numeric digits.*/
     @@@=@@@'<>[]{}()?~!@#$%^&*_=|\/;:¢¬≈'            /*add some special chars as well.*/
                            /* [↑]  handles up to base 90,  all chars must be viewable.*/
     numeric digits 3000                              /*what the hey, support gihugeics*/
     mxB=length(@@@)                                  /*max base (radix) supported here*/
     if toB== | toB=="," then toB=10                /*if skipped, assume default (10)*/
     if inB== | inB=="," then inB=10                /* "    "        "      "      " */
     if inB<2   | inb>mxB  then call erb 'inBase',inB /*invalid/illegal arg:   inBase. */
     if toB<2   | tob>mxB  then call erb 'toBase',toB /*    "      "     "     toBase. */
     if x==              then call erm              /*    "      "     "     number. */
            sigX=left(x, 1)                           /*obtain a possible leading sign.*/
     if pos(sigX, '-+')\==0  then x=substr(x, 2)      /*X  number has a leading sign?  */
                             else sigX=               /*           ··· no leading sign.*/
     #=0
           do j=1  for length(x);  _=substr(x, j, 1)  /*convert X, base inB ──► base 10*/
           v=pos(_, @@@)                              /*get the value of this "digit". */
           if v==0 | v>inB  then call erd x,j,inB     /*is this an illegal "numeral" ? */
           #=# * inB + v - 1                          /*construct new num, dig by dig. */
           end   /*j*/
     y=
           do  while  # >= toB                        /*convert #, base 10 ──► base toB*/
           y=substr(@@@, (# // toB) + 1, 1)y          /*construct the number for output*/
           #=# % toB                                  /* ··· and whittle  #  down also.*/
           end   /*while*/
     y=sigX || substr(@@@, #+1, 1)y                   /*prepend the sign if it existed.*/
     return y                                         /*return the number in base  toB.*/

/*──────────────────────────────────────────────────────────────────────────────────────*/ erb: call ser 'illegal' arg(2) "base: " arg(1) "must be in range: 2──► " mxB erd: call ser 'illegal "digit" in' x":" _ erm: call ser 'no argument specified.' ser: say; say '***error***'; say arg(1); say; exit 13</lang>

output   when using the input of:   6   2
displaying a  6  row Floyd's triangle in base 2:
 
    1
   10    11
  100   101   110
  111  1000  1001  1010
 1011  1100  1101  1110  1111
10000 10001 10010 10011 10100 10101
output   when using the input of:   23   2
displaying a  12  row Floyd's triangle in base 2:

      1
     10      11
    100     101     110
    111    1000    1001    1010
   1011    1100    1101    1110    1111
  10000   10001   10010   10011   10100   10101
  10110   10111   11000   11001   11010   11011   11100
  11101   11110   11111  100000  100001  100010  100011  100100
 100101  100110  100111  101000  101001  101010  101011  101100  101101
 101110  101111  110000  110001  110010  110011  110100  110101  110110  110111
 111000  111001  111010  111011  111100  111101  111110  111111 1000000 1000001 1000010
1000011 1000100 1000101 1000110 1000111 1001000 1001001 1001010 1001011 1001100 1001101 1001110
output   when using the input of:   40   81
displaying a  40  row Floyd's triangle in base 81:

 1
 2  3
 4  5  6
 7  8  9  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  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  <  >  [  ]  {
 }  (  )  ?  ~  !  @  #  $  %  ^  &
 *  _ 10 11 12 13 14 15 16 17 18 19 1a
1b 1c 1d 1e 1f 1g 1h 1i 1j 1k 1l 1m 1n 1o
1p 1q 1r 1s 1t 1u 1v 1w 1x 1y 1z 1A 1B 1C 1D
1E 1F 1G 1H 1I 1J 1K 1L 1M 1N 1O 1P 1Q 1R 1S 1T
1U 1V 1W 1X 1Y 1Z 1< 1> 1[ 1] 1{ 1} 1( 1) 1? 1~ 1!
1@ 1# 1$ 1% 1^ 1& 1* 1_ 20 21 22 23 24 25 26 27 28 29
2a 2b 2c 2d 2e 2f 2g 2h 2i 2j 2k 2l 2m 2n 2o 2p 2q 2r 2s
2t 2u 2v 2w 2x 2y 2z 2A 2B 2C 2D 2E 2F 2G 2H 2I 2J 2K 2L 2M
2N 2O 2P 2Q 2R 2S 2T 2U 2V 2W 2X 2Y 2Z 2< 2> 2[ 2] 2{ 2} 2( 2)
2? 2~ 2! 2@ 2# 2$ 2% 2^ 2& 2* 2_ 30 31 32 33 34 35 36 37 38 39 3a
3b 3c 3d 3e 3f 3g 3h 3i 3j 3k 3l 3m 3n 3o 3p 3q 3r 3s 3t 3u 3v 3w 3x
3y 3z 3A 3B 3C 3D 3E 3F 3G 3H 3I 3J 3K 3L 3M 3N 3O 3P 3Q 3R 3S 3T 3U 3V
3W 3X 3Y 3Z 3< 3> 3[ 3] 3{ 3} 3( 3) 3? 3~ 3! 3@ 3# 3$ 3% 3^ 3& 3* 3_ 40 41
42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f 4g 4h 4i 4j 4k 4l 4m 4n 4o 4p 4q 4r
4s 4t 4u 4v 4w 4x 4y 4z 4A 4B 4C 4D 4E 4F 4G 4H 4I 4J 4K 4L 4M 4N 4O 4P 4Q 4R 4S
4T 4U 4V 4W 4X 4Y 4Z 4< 4> 4[ 4] 4{ 4} 4( 4) 4? 4~ 4! 4@ 4# 4$ 4% 4^ 4& 4* 4_ 50 51
52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f 5g 5h 5i 5j 5k 5l 5m 5n 5o 5p 5q 5r 5s 5t 5u
5v 5w 5x 5y 5z 5A 5B 5C 5D 5E 5F 5G 5H 5I 5J 5K 5L 5M 5N 5O 5P 5Q 5R 5S 5T 5U 5V 5W 5X 5Y
5Z 5< 5> 5[ 5] 5{ 5} 5( 5) 5? 5~ 5! 5@ 5# 5$ 5% 5^ 5& 5* 5_ 60 61 62 63 64 65 66 67 68 69 6a
6b 6c 6d 6e 6f 6g 6h 6i 6j 6k 6l 6m 6n 6o 6p 6q 6r 6s 6t 6u 6v 6w 6x 6y 6z 6A 6B 6C 6D 6E 6F 6G
6H 6I 6J 6K 6L 6M 6N 6O 6P 6Q 6R 6S 6T 6U 6V 6W 6X 6Y 6Z 6< 6> 6[ 6] 6{ 6} 6( 6) 6? 6~ 6! 6@ 6# 6$
6% 6^ 6& 6* 6_ 70 71 72 73 74 75 76 77 78 79 7a 7b 7c 7d 7e 7f 7g 7h 7i 7j 7k 7l 7m 7n 7o 7p 7q 7r 7s
7t 7u 7v 7w 7x 7y 7z 7A 7B 7C 7D 7E 7F 7G 7H 7I 7J 7K 7L 7M 7N 7O 7P 7Q 7R 7S 7T 7U 7V 7W 7X 7Y 7Z 7< 7>
7[ 7] 7{ 7} 7( 7) 7? 7~ 7! 7@ 7# 7$ 7% 7^ 7& 7* 7_ 80 81 82 83 84 85 86 87 88 89 8a 8b 8c 8d 8e 8f 8g 8h 8i
8j 8k 8l 8m 8n 8o 8p 8q 8r 8s 8t 8u 8v 8w 8x 8y 8z 8A 8B 8C 8D 8E 8F 8G 8H 8I 8J 8K 8L 8M 8N 8O 8P 8Q 8R 8S 8T
8U 8V 8W 8X 8Y 8Z 8< 8> 8[ 8] 8{ 8} 8( 8) 8? 8~ 8! 8@ 8# 8$ 8% 8^ 8& 8* 8_ 90 91 92 93 94 95 96 97 98 99 9a 9b 9c
9d 9e 9f 9g 9h 9i 9j 9k 9l 9m 9n 9o 9p 9q 9r 9s 9t 9u 9v 9w 9x 9y 9z 9A 9B 9C 9D 9E 9F 9G 9H 9I 9J 9K 9L 9M 9N 9O 9P
9Q 9R 9S 9T 9U 9V 9W 9X 9Y 9Z 9< 9> 9[ 9] 9{ 9} 9( 9) 9? 9~ 9! 9@ 9# 9$ 9% 9^ 9& 9* 9_ a0 a1 a2 a3 a4 a5 a6 a7 a8 a9 aa

Ring

<lang ring> rows = 10 n = 0 for r = 1 to rows

   for c = 1 to r  
       n = n + 1
       see string(n) + " " 
   next 
   see nl

next

</lang> Output:

1 
2 3 
4 5 6 
7 8 9 10 
11 12 13 14 15 
16 17 18 19 20 21 
22 23 24 25 26 27 28 
29 30 31 32 33 34 35 36 
37 38 39 40 41 42 43 44 45 
46 47 48 49 50 51 52 53 54 55 
56 57 58 59 60 61 62 63 64 65 66 
67 68 69 70 71 72 73 74 75 76 77 78 
79 80 81 82 83 84 85 86 87 88 89 90 91 
92 93 94 95 96 97 98 99 100 101 102 103 104 105 

Ruby

<lang ruby>def floyd(rows)

 max = (rows * (rows + 1)) / 2
 widths = ((max - rows + 1)..max).map {|n| n.to_s.length + 1}
 n = 0
 rows.times do |r|
   puts (0..r).map {|i| n += 1; "%#{widths[i]}d" % n}.join
 end

end

floyd(5) floyd(14)</lang>

Output:
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

Run BASIC

<lang runbasic>input "Number of rows: "; rows dim colSize(rows) for col=1 to rows

   colSize(col) = len(str$(col + rows * (rows-1)/2))

next

thisNum = 1 for r = 1 to rows

   for col = 1 to r
       print right$( "  "+str$(thisNum), colSize(col)); " ";
       thisNum = thisNum + 1
   next
   print

next</lang>

Number of rows: ?14
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 
16 17 18 19 20 21 
22 23 24 25 26 27 28 
29 30 31 32 33 34 35 36 
37 38 39 40 41 42 43 44  45 
46 47 48 49 50 51 52 53  54  55 
56 57 58 59 60 61 62 63  64  65  66 
67 68 69 70 71 72 73 74  75  76  77  78 
79 80 81 82 83 84 85 86  87  88  89  90  91 
92 93 94 95 96 97 98 99 100 101 102 103 104 105 

Rust

<lang rust>fn main() {

   floyds_triangle(5);
   floyds_triangle(14);

}

fn floyds_triangle(n: u32) {

   let mut triangle: Vec<Vec<String>> = Vec::new();
   let mut current = 0;
   for i in 1..=n {
       let mut v = Vec::new();
       for _ in 0..i {
           current += 1;
           v.push(current);
       }
       let row = v.iter().map(|x| x.to_string()).collect::<Vec<_>>();
       triangle.push(row);
   }
   for row in &triangle {
       let arranged_row: Vec<_> = row
           .iter()
           .enumerate()
           .map(|(i, number)| {
               let space_len = triangle.last().unwrap()[i].len() - number.len() + 1;
               let spaces = " ".repeat(space_len);
               let mut padded_number = spaces;
               padded_number.push_str(&number);
               padded_number
           })
           .collect();
       println!("{}", arranged_row.join(""))
   }

}

</lang>

Scala

<lang scala>def floydstriangle( n:Int ) = {

 val s = (1 to n)
 val t = s map {i => (s.take(i-1).sum) + 1}
 
 (s zip t) foreach { n => 
   var m = n._2; 
   for( i <- 0 until n._1 ) {
     val w = (t.last + i).toString.length + 1  // Column width from last row
     print("           " + m takeRight w )
     m+=1
   }
   print("\n")
 }

}

// Test floydstriangle(5) floydstriangle(14)</lang>

Output:
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15

  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

Seed7

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

const proc: writeFloyd (in integer: rows) is func

 local
   var integer: number is 1;
   var integer: numBeforeLastLine is 0;
   var integer: line is 0;
   var integer: column is 0;
 begin
   numBeforeLastLine := rows * pred(rows) div 2;
   for line range 1 to rows do
     for column range 1 to line do
       if column <> 1 then
         write(" ");
       end if;
       write(number lpad length(str(numBeforeLastLine + column)));
       incr(number);
     end for;
     writeln;
   end for;
 end func;

const proc: main is func

 begin
   writeFloyd(5);
   writeFloyd(14);
 end func;</lang>

Output:

 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35 36
37 38 39 40 41 42 43 44  45
46 47 48 49 50 51 52 53  54  55
56 57 58 59 60 61 62 63  64  65  66
67 68 69 70 71 72 73 74  75  76  77  78
79 80 81 82 83 84 85 86  87  88  89  90  91
92 93 94 95 96 97 98 99 100 101 102 103 104 105

Sidef

<lang ruby>func floyd(rows, n=1) {

   var max = Math.range_sum(1, rows)
   var widths = (max-rows .. max-1 -> map{.+n->to_s.len})
   { |r|
       say %'#{1..r -> map{|i| "%#{widths[i-1]}d" % n++}.join(" ")}'
   } << 1..rows

}

floyd(5) # or: floyd(5, 88) floyd(14) # or: floyd(14, 900)</lang>

Output:
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35 36
37 38 39 40 41 42 43 44  45
46 47 48 49 50 51 52 53  54  55
56 57 58 59 60 61 62 63  64  65  66
67 68 69 70 71 72 73 74  75  76  77  78
79 80 81 82 83 84 85 86  87  88  89  90  91
92 93 94 95 96 97 98 99 100 101 102 103 104 105

SPL

<lang spl>floyd(5) floyd(14)

floyd(n)=

 k = 0
 > r, 1..n
   s = ""
   > j, 1..r
     k += 1
     f = ">"+#.upper(#.log10((n-1)*n/2+j+1)+1)+">"
     s += #.str(k,f)
   <
   #.output(s)
 <

.</lang>

Output:
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

Tcl

<lang tcl>proc floydTriangle n {

   # Compute the column widths
   for {set i [expr {$n*($n-1)/2+1}]} {$i <= $n*($n+1)/2} {incr i} {

lappend w [string length $i]

   }
   # Print the triangle
   for {set i 0; set j 1} {$j <= $n} {incr j} {

for {set p -1; set k 0} {$k < $j} {incr k} { puts -nonewline [format "%*d " [lindex $w [incr p]] [incr i]] } puts ""

   }

}

  1. Demonstration

puts "Floyd 5:" floydTriangle 5 puts "Floyd 14:" floydTriangle 14</lang>

Output:
Floyd 5:
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 
Floyd 14:
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 
16 17 18 19 20 21 
22 23 24 25 26 27 28 
29 30 31 32 33 34 35 36 
37 38 39 40 41 42 43 44  45 
46 47 48 49 50 51 52 53  54  55 
56 57 58 59 60 61 62 63  64  65  66 
67 68 69 70 71 72 73 74  75  76  77  78 
79 80 81 82 83 84 85 86  87  88  89  90  91 
92 93 94 95 96 97 98 99 100 101 102 103 104 105 

TXR

<lang txrlisp>(defun flotri (n)

 (let* ((last (trunc (* n (+ n 1)) 2))
        (colw (mapcar [chain tostring length]
                      (range (- last n -1) last)))
        (x 0))
   (each ((r (range* 0 n)))
     (each ((c (range 0 r)))
       (format t " ~*a" [colw c] (inc x)))
     (put-line))))

(defun usage (msg)

 (put-line `error: @msg`)
 (put-line `usage:\n@(ldiff *full-args* *args*) <smallish-positive-integer>`)
 (exit 1))

(tree-case *args*

 ((num blah . etc) (usage "too many arguments"))
 ((num) (flotri (int-str num)))
 (() (usage "need an argument")))</lang>
Output:
$ txr floyds-triangle.tl
error: need an argument
usage:
txr floyds-triangle.tl <smallish-positive-integer>
$ txr floyds-triangle.txr 1 2
error: too many arguments
usage:
txr floyds-triangle.tl <smallish-positive-integer>
$ txr floyds-triangle.tl 5
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
$ txr floyds-triangle.tl 14
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

VBA

Solution in Microsoft Office Word. Based on VBScript <lang VB>Option Explicit Dim o As String Sub floyd(L As Integer)

   Dim r, c, m, n As Integer
   n = L * (L - 1) / 2
   m = 1
   For r = 1 To L
       o = o & vbCrLf
       For c = 1 To r
           o = o & Space(Len(CStr(n + c)) - Len(CStr(m))) & m & " "
           m = m + 1
       Next
   Next

End Sub Sub triangle()

   o = "5 lines"
   Call floyd(5)
   o = o & vbCrLf & "14 lines"
   Call floyd(14)
   With Selection
       .Font.Name = "Courier New"
       .TypeText Text:=o
   End With

End Sub</lang>

Output:

<lang>5 lines

1 
2  3 
4  5  6 
7  8  9 10 

11 12 13 14 15

14 lines

1 
2  3 
4  5  6 
7  8  9 10 

11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105</lang>

VBScript

Works with: Windows Script Host version *

<lang VBScript> ' Read the number of rows to use.. intRows = WScript.StdIn.ReadLine

' Get the first number of the final row so we can calculate widths... intLastRowStart = (intRows ^ 2 - intRows) \ 2 + 1

For i = 1 To intRows intLastRow = intLastRowStart For j = 1 To i k = k + 1 WScript.StdOut.Write Space(Len(intLastRow) - Len(k)) & k & " " intLastRow = intLastRow + 1 Next WScript.StdOut.WriteLine "" Next </lang>

Visual Basic .NET

Translation of: C#

<lang vbnet>Imports System.Text

Module Module1

   Function MakeTriangle(rows As Integer) As String
       Dim maxValue As Integer = (rows * (rows + 1)) / 2
       Dim digit = 0
       Dim output As New StringBuilder
       For row = 1 To rows
           For column = 0 To row - 1
               Dim colMaxDigit = (maxValue - rows) + column + 1
               If column > 0 Then
                   output.Append(" ")
               End If
               digit = digit + 1
               output.Append(digit.ToString().PadLeft(colMaxDigit.ToString().Length))
           Next
           output.AppendLine()
       Next
       Return output.ToString()
   End Function
   Sub Main()
       Dim args = Environment.GetCommandLineArgs()
       Dim count As Integer
       If args.Length > 1 AndAlso Integer.TryParse(args(1), count) AndAlso count > 0 Then
           Console.WriteLine(MakeTriangle(count))
       Else
           Console.WriteLine(MakeTriangle(5))
           Console.WriteLine()
           Console.WriteLine(MakeTriangle(14))
       End If
   End Sub

End Module</lang>

Output:
 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15


 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31 32 33 34 35 36
37 38 39 40 41 42 43 44  45
46 47 48 49 50 51 52 53  54  55
56 57 58 59 60 61 62 63  64  65  66
67 68 69 70 71 72 73 74  75  76  77  78
79 80 81 82 83 84 85 86  87  88  89  90  91
92 93 94 95 96 97 98 99 100 101 102 103 104 105

Wren

Library: Wren-fmt

<lang ecmascript>import "/fmt" for Fmt

var floyd = Fn.new { |n|

  var k = 1
  for (i in 1..n) {
      for (j in 1..i) {
          Fmt.write("$*d ", (j < 9) ? 2 : 3, k)
          k = k + 1
      }
      System.print()
  }

}

System.print("Floyd(5):") floyd.call(5) System.print("\nFloyd(14):") floyd.call(14)</lang>

Output:
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 

Floyd(14):
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 
16 17 18 19 20 21 
22 23 24 25 26 27 28 
29 30 31 32 33 34 35 36 
37 38 39 40 41 42 43 44  45 
46 47 48 49 50 51 52 53  54  55 
56 57 58 59 60 61 62 63  64  65  66 
67 68 69 70 71 72 73 74  75  76  77  78 
79 80 81 82 83 84 85 86  87  88  89  90  91 
92 93 94 95 96 97 98 99 100 101 102 103 104 105 

XPL0

<lang XPL0>include c:\cxpl\codes; \include 'code' declarations

func IntLen(N); \Return number of digits in a positive integer int N; int I; for I:= 1 to 20 do

   [N:= N/10;  if N=0 then return I];

proc Floyd(N); \Display Floyd's triangle int N; int M, Row, Col; real F; [M:= (N-1+1)*(N-1)/2; \last Floyd number on second to last row F:= 1.0; \Floyd number counter for Row:= 1 to N do

   [for Col:= 1 to Row do
       [Format(IntLen(M+Col)+1, 0);  RlOut(0, F);  F:= F+1.0];
   CrLf(0);
   ];

]; \Floyd

[Floyd(5); Floyd(14); ]</lang>

Output:

  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
  1
  2  3
  4  5  6
  7  8  9 10
 11 12 13 14 15
 16 17 18 19 20 21
 22 23 24 25 26 27 28
 29 30 31 32 33 34 35 36
 37 38 39 40 41 42 43 44  45
 46 47 48 49 50 51 52 53  54  55
 56 57 58 59 60 61 62 63  64  65  66
 67 68 69 70 71 72 73 74  75  76  77  78
 79 80 81 82 83 84 85 86  87  88  89  90  91
 92 93 94 95 96 97 98 99 100 101 102 103 104 105

zkl

Format last line and then fit each line to that format (which is wider than terminal width before formating breaks down (at 10 digit numbers)): <lang zkl>fcn lcNum(row){(row*(row+1)/2+1)} // lazy caterer's sequence fcn floydsTriangle(rows){

  fmt:=[lcNum(rows-1)..lcNum(rows)-1].pump(String,fcn(n){
     String("%",n.toString().len(),"d ")}); // eg "%2d %2d %3d %3d"
  foreach row in (rows){
    ns:=[lcNum(row)..lcNum(row+1)-1].walk(); // eg L(4.5,6)
    fmt[0,ns.len()*4].fmt(ns.xplode()).println(); // eg "%2d %2d %2d ".fmt(4,5,6)
  }

} floydsTriangle(5); println(); floydsTriangle(14);</lang>

Output:
 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 

 1 
 2  3 
 4  5  6 
 7  8  9 10 
11 12 13 14 15 
16 17 18 19 20 21 
22 23 24 25 26 27 28 
29 30 31 32 33 34 35 36 
37 38 39 40 41 42 43 44  45 
46 47 48 49 50 51 52 53  54  55 
56 57 58 59 60 61 62 63  64  65  66 
67 68 69 70 71 72 73 74  75  76  77  78 
79 80 81 82 83 84 85 86  87  88  89  90  91 
92 93 94 95 96 97 98 99 100 101 102 103 104 105 

ZX Spectrum Basic

<lang zxbasic>10 LET n=10: LET j=1: LET col=1 20 FOR r=1 TO n 30 FOR j=j TO j+r-1 40 PRINT TAB (col);j; 50 LET col=col+3 60 NEXT j 70 PRINT 80 LET col=1 90 NEXT r</lang>