Semi-Diagonal Alphabet

Question

Given a letter of the English alphabet, your task is to build a semi-diagonal alphabet to the input.

How to build a Semi-Diagonal alphabet?

Brief Description: First, you take the position of the letter in the alphabet, P (P is 1-indexed here). Then, you print each letter until the input (inclusive) on a line, preceded by P-1 and repeat that letter P times, interleaving with spaces.

Examples:

• Given F, your program should output:

  A 
   B B 
    C C C 
     D D D D 
      E E E E E 
       F F F F F F 
  

• Given K, your program should output:

  A
   B B 
    C C C 
     D D D D 
      E E E E E 
       F F F F F F 
        G G G G G G G 
         H H H H H H H H 
          I I I I I I I I I 
           J J J J J J J J J J 
            K K K K K K K K K K K 
  

• Given A, your program should output:

  A
  

Rules

• You may choose either lowercase or uppercase characters, but that should be consistent.

• You may have extraneous spaces as follows:

  • One consistent leading space (on each line).
  • A trailing or leading newline(s).
  • Trailing spaces.

• Input and output can be taken by any standard mean, and default loopholes apply.

• You are allowed to output a list of lines instead, as long as you also provide the ascii-art version.

• This is code-golf, so the shortest code in bytes wins!

^{Inspired by this challenge.}

Answer 1

Python 3, 59 bytes

lambda l:[' '*i+'%c '%(i+65)*-~i for i in range(ord(l)-64)]

Try it online!

Python 3, 61 bytes

lambda l:[' '*i+-~i*(chr(i+65)+' ')for i in range(ord(l)-64)]

Try it online! (link to pretty-print version)

Answer 2

Python 2, 63 61 59 bytes

-2 bytes thanks to Rod. -2 bytes thanks to Felipe Nardi Batista.

i=1
exec"print' '*i+'%c '%(i+64)*i;i+=1;"*(ord(input())-64)

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Answer 3

C, 89 bytes

i,j;f(l){for(i=64;i++<l&&printf("%*c ",i-64,i);puts(""))for(j=i-65;j--;)printf("%c ",i);}

Try it online!

Answer 4

PowerShell, 45 42 bytes

65..$args[0]|%{" "*$i+++"$([char]$_) "*$i}

Try it online!

Takes input as a literal char, then loops up through the capitals to that point, each iteration prepending the appropriate number of spaces and then the char\space hybrid.

Saved 3 bytes thanks to TessellatingHeckler.

Answer 5

JavaScript (ES6), 85 bytes

Works in lower case for both input and output. Outputs a leading space and a trailing space on each line.

f=(c,k=10,C=k.toString(36),r=s=>`${s} `.repeat(k-9))=>r``+r(C)+(C==c?'':`
`+f(c,k+1))

Demo

f=(c,k=10,C=k.toString(36),r=s=>`${s} `.repeat(k-9))=>r``+r(C)+(C==c?'':`
`+f(c,k+1))

O.innerText = f('m')

<pre id=O>

Answer 6

APL (Dyalog), 26 bytes

Prompts for scalar character. Prints list of lines.

(∊⍴∘'',' ',¨⍨⊢⍴⊃∘⎕A)¨⍳⎕A⍳⎕

Try it online! (has ASCII art version at one additional byte)

⎕ prompt for input

⎕A⍳ find ɩndex in Alphabet

⍳ first that many ɩntegers

(…)¨ apply the following tacit function to each :

 ⊃∘⎕A pick the argument'th letter letter from the Alphabet

 ⊢⍴ cyclically reshape it to the argument length

 ' ',¨⍨ append a space to each

 ⍴∘'', prepend a string of argument length (padded with spaces)

 ∊ ϵnlist (flatten)

---

The ASCII art version just has a ↑ on the very left; mix list of strings into table of characters.

Answer 7

Perl 5, 31 bytes

30 bytes code + 1 for -l.

print$"x$-,"$_ "x++$-for A..<>

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Answer 8

Dyalog APL, 38 bytes

{↑{(y/' '),(2×y←⎕A⍳⍵)⍴⍵,' '}¨⎕A↑⍨⎕A⍳⍵}

Try it online!

How?

⎕A↑⍨ - take the alphabet until

⎕A⍳⍵ - the input character

¨ - for each char

    ⍵,' ' - take the char and a space

    (...)⍴ - reshape to

    2×y←⎕A⍳⍵ - twice the index of the char in the alphabet

    (y/' ') - and prepend index-of-char spaces

↑ - then flatten

Answer 9

APL (Dyalog Classic), 26 bytes

{↑{(≠\⍵<⍳3×⍵)\⍵⊃⎕A}¨⍳⎕A⍳⍵}

Try it online!

Explanation

                      ⍳⎕A⍳⍵  generate indexes up to position of right arg ⍵
{                   }¨       on each index apply function
   (≠\⍵<⍳3×⍵)                generate boolean mask for expansion (each line has a length 3 times its index ⍵, starting with ⍵ blanks and then alternating letter blank)
             \⍵⊃⎕A          expand character in position ⍵
 ↑                            mix result into text matrix

Answer 10

V, 28, 26, 25, 23 bytes (Competing)

¬A[/a
lDÓ./& ò
ò-Ûä$Û>

Try it online!

Note that although I have been planning on adding certain features for a long time, this challenge was what convinced me to finally do it.

The output contains one leading space on each line and one trailing newline.

Hexdump:

00000000: ac41 5b2f 1261 0a6c 44d3 2e2f 2620 f20a  .A[/.a.lD../& ..
00000010: f22d dbe4 24db 3e                        .-..$.>

Explanation:

¬A[         " Insert 'ABCDEFGHIJKLMNOPQRSTUVWXYZ['
   /        " Search for...
    <C-r>a  "   The input
l           " Move one character to the right
 D          " And delete every character after the cursor
  Ó         " Search for...
   .        "   Any character
    /       " And replace it with...
     & ò    "   That character followed by a space and a newline
ò           " Recursively...
 -          "   Move to the beginning of the next line up
  Ûä$       "   Make *line number* copies of the current line
     Û>     "   And indent this line by *line number* spaces

Answer 11

Husk, 13 bytes

z+ḣ∞øzRNC1…'A

Takes a character in single quotes as command line argument, prints result to STDOUT. Try it online!

Explanation

I'm exploiting the way Husk prints lists of lists of strings: join inner lists with spaces and outer lists with newlines.

z+ḣ∞øzRNC1…'A  Implicit input, say 'C'
          …'A  Range from A: "ABC"
        C1     Cut into strings of length 1: ["A","B","C"]
     z N       Zip with positive integers
      R        using repetition: x = [["A"],["B","B"],["C","C","C"]]
   ∞ø          The empty string repeated infinitely: ["","","",...
  ḣ            Prefixes: [[],[""],["",""],["","",""],...
z+             Zip with x using concatenation: [["A"],["","B","B"],["","","C","C","C"]]
               Implicitly join each inner list with spaces, join the resulting strings with newlines and print.

Answer 12

05AB1E, 10 bytes

A¹¡н«ðâƶāú

Try it online!

-2 thanks to Adnan.

Append » to make it print in separate lines.

Answer 13

R, 94 88 bytes

-6 bytes thanks to Giuseppe

function(x,l=LETTERS)for(i in 1:match(x,l))cat(rep(' ',i-1),rep(paste(l[i],' '),i),'\n')}

Ungolfed:

f=function(x,l=letters){
  for(i in 1:which(l==x)){
    A=paste(l[i],' ')
    cat(rep(' ',i-1),rep(A,i),'\n')
  }
}

Answer 14

Haskell, 52 44 bytes

f k=[[" ",s:" "]>>=(['A'..s]>>)|s<-['A'..k]]

Returns a list of lines.

Try it online!

f k=                  -- main function is f, input parameter k
  [   |s<-['A'..k]]   -- for each s from ['A'..k]
     >>=              -- map (and collect the results in a single string) the function: 
         (['A'..s]>>) --  replace each element in ['A'..s] with
    [  ,  ]           --  over the list, containing
     " "              --   a single space to get the indent
        s:" "         --   s followed by space to get the letter sequence

Edit: @jferard: saved three bytes. Thanks!

Answer 15

JavaScript (ES8), 92 bytes

c=>(g=n=>n>9?[...g(n-1),`${n.toString(36)} `.repeat(n-=9).padStart(n*3)]:[])(parseInt(c,36))

Uses lowercase letters. Lines have one leading and one trailing space. Returns an array of lines.

Test Snippet

let f=

c=>(g=n=>n>9?[...g(n-1),`${n.toString(36)} `.repeat(n-=9).padStart(n*3)]:[])(parseInt(c,36))

;O.innerText=f("k").join`\n`

<pre id=O></pre>

Answer 16

05AB1E, 15 14 13 bytes

Saved 1 byte thanks to Adnan

A¹¡н«ƶ€S»¶¡āú»

Try it online! or the Ascii art version

Explanation

A                # push lowercase alphabet
 ¹¡              # split at input
   н             # get the first part
    «            # append the input
     ƶ           # repeat each a number of times corresponding to its 1-based index
      €S         # split each to a list of chars
        »        # join on spaces and newlines
         ¶¡      # split on newlines
           āú    # prepend spaces to each corresponding to its 1-based index
             »   # join on newlines

Answer 17

APL (Dyalog Unicode), 22 bytes^SBCS

⍕⍪⊢∘⊂\2,.↑⍉⍴⍨⌸⎕a↑⍨⎕a⍳⍞

Try it online!

Uses ⎕io←1. Prints a leading space, which is allowed.

Answer 18

QBasic, 79 74 72 bytes

Thanks to Taylor Scott for byte savings (twice!)

FOR i=1TO ASC(INPUT$(1))-64
?TAB(i)
FOR j=1TO i
?CHR$(64+i)" ";
NEXT j,i

Uses uppercase. The input is by keypress and is not echoed to the screen.

Explanation

We loop i from 1 up to the limiting letter's position in the alphabet (1-based). For each i, we move to column i of the screen using TAB; then, i times, we print the ith letter of the alphabet followed by a space.

Answer 19

Japt -R, 24 23 17 15 bytes

Outputs an array, includes a leading newline and a leading & trailing space on each line.

IòUc ÏçSiXd¹iYç

Test it

• 1 byte saved with help from Oliver and a further 6 thanks to him pointing out a better way to generate the initial array.

Answer 20

Charcoal, 18 bytes

Ｆ⁺⌕αθ¹«Ｐ×⁺§αι ⁺ι¹↘

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Answer 21

Braingolf, 65 bytes

a#a-# 7-,-~vc<!?>[$_]:$_|&,(.#a-!?.>[# M]1+>[.M# M]:$_!@|v#
&@R);

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Lowercase.

Contains 1 trailing space on each line, and a trailing newline at the end of output.

Answer 22

C# (.NET Core), 103 bytes

n=>{var i='`';var l="";for(;i<n;l+='\n'){l+="".PadLeft(i++-96);for(int s=96;s++<i;)l+=i+" ";}return l;}

Try it online!

Answer 23

JavaScript, 102 94 bytes

2 bytes saved thanks to Neil

f=
a=>[...Array(parseInt(a,36)-9)].map((a,b)=>''.padEnd(b).padEnd(b*3+1,(b+10).toString(36)+' '))

console.log(f('k').join`\n`)

Answer 24

Retina, 51 bytes

^.
$&$&
}T`L`_L`^.
.
$.`$* $&$.`$* ¶
+`(\w) \B
$&$1

Try it online! Explanation:

^.
$&$&

Duplicate the (first) letter.

}T`L`_L`^.

Rotate it back 1 in the alphabet, or delete it if it's a duplicate A. Keep duplicating and rotating until we duplicate A, at which point the deletion undoes the duplication and the loop completes.

.
$.`$* $&$.`$* ¶

Replace each letter with a line with the letter padded on both sides.

+`(\w) \B
$&$1

Insert duplicate letters between all pairs of padding spaces to the right of existing letters.

Answer 25

Haskell, 57 bytes

x!'@'=x
x!e=([e]:[' ':r++' ':[last r]|r<-x])!pred e
([]!)

Try it online!

Answer 26

Charcoal, 15 bytes

Ｆ…·AＳ«Ｐ⪫Ｅ…@ιι ↘

Try it online! Link is to verbose version of code. Explanation:

 …·AＳ           Inclusive character range from A to the input
Ｆ    «          Loop over each character
         …@ι    Exclusive range from @ to the current character
        Ｅ   ι   Replace each element with the current character
       ⪫        Join with spaces
      Ｐ         Print without moving the cursor.
              ↘ Move the cursor down and right.

If extra padding was legal, this would work for 14 bytes:

Ｅ…·?θ⁺× κ⪫× κι

Try it online! Link is to verbose version of code.

Answer 27

Mathematica, 70 bytes

(T=Table)[""<>{" "~T~i,T[Alphabet[][[i]]<>" ",i]},{i,LetterNumber@#}]&

lowercase

outputs a list

thanx @ngenisis for corrections

For ascii-art version place Column@ at the beginning

Answer 28

Excel VBA, 72 Bytes

Anonymous VBE immediate window function that takes input from cell A1 and outputs to the VBE immediate window

For i=1To Asc([A1])-64:[B1]=i:?Space(i-1)[REPT(CHAR(B1+64)&" ",B1)]:Next

Answer 29

Pyth, 17 bytes

.e+*kd*+bdhk<GhxG

Try it here (pretty print version).

---

How does this work?

• hxG - Takes the index of the input in the lowercase alphabet.

• <G - Trims every character after the input from the alphabet.

• .e - Enumerated Map. Maps over the trimmed alphabet with the indexes as k and the letters as b.

• *kd - Append k spaces.

• +bd - b + a space (the current letter + space).

• *...hk - Repeat k+1 times.

• +(...)(...) - Concatenate.

Answer 30

C++ (gcc), 164 bytes

#include<iostream>
#define f for(int i=0;i<o-'`';i++)
using namespace std;int main(){char c;cin>>c;for(char o='a';o<=c;o++){f cout<<' ';f cout<<o<<' ';cout<<'\n';}}

My first attempt after a long time lurking!

Ungolfed code below:

#include <iostream>

using namespace std;
#define f for (auto i = 0; i < output - '`'; i++)

int main()
{
  char input;

  cin >> input;

  for (char output = 'a'; output <= input; output++)
  {
    f cout << ' ';

    f cout << output << ' ';

    cout << endl;
  }
}

Try it online!