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 .}

• Adám: Is output as list of strings ok?
• user70974: Why the downvote? What can i improve?
• Dave: When you say "P is 1-indexed here", does here refer to the challenge or the example?
• user70974: @pizzakingme No, you may not.
• sergiol: I accidentlly got an interesting pattern while golfing my answer: tio.run/##K0nO@f@/…

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)

• Mr. Xcoder: I see absolutely no reason for a downvote. Can the @downvoter explain?
• Conor O'Brien: I'd imagine it's just a misclick, or perhaps someone not liking a lack of explanation (the latter is quite unlikely IMO)
• Thomas Weller: I dislike Python and I can't implement with Python, so the answer is not useful for me? Just kidding, but the button tooltips probably do not fit the rules of this site
• Stan Strum: Is it just me or does it say Mr. Xcoder has 1 rep...?

Answer 2

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 3

Python 2, (削除) 63 (削除ここまで) (削除) 61 (削除ここまで) 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)

Try it online!

Answer 4

PowerShell, (削除) 45 (削除ここまで) 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.

• AdmBorkBork: @TessellatingHeckler Indeed. I've been golfing that to "$args" so much, which wouldn't work here, I forgot about the [0] method. Haha.

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>

• Luke: `${s} ` can be replaced by (s+"") for one byte saving
• Arnauld: @Luke I need this space. It can be replaced by (s+" "), but that's just as long.

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..<>

Try it online!

• Xcali: You can cut this down by using say instead of the -l flag: Try it online!
• Dom Hastings: @Xcali I'm torn on -E/-M5.01, I've used say considerably in the past, and would probably abuse the fact that say is an alternative to print in a restricted source challenge or similar perhaps, but for the sake of -3, I'll keep as-is for now. See this meta post for a fair argument. Appreciate the input though!

Answer 8

Dyalog APL, 38 bytes

{↑{(y/' '),(×ばつ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

×ばつ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

{↑{(≠\⍵&l×ばつ⍵)\⍵⊃⎕A} ̈⍳⎕A⍳⍵}

Try it online!

Explanation

 ⍳⎕A⍳⍵ generate indexes up to position of right arg ⍵
{ } ̈ on each index apply function
 (≠\⍵&l×ばつ⍵) 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

• ngn: Goodness... 4 APL-er solving the same problem at the same time! :) I think in codegolf you're allowed to remove the outer {}, replace ⍵ with ⎕, and claim it's a "complete program" rather than a function. That would make your solution the best (so far).
• Gil: Must be a good sign :) Thanks for the suggestion. I've seen it done but wasn't sure where to draw the line. I guess that I can save 3 bytes if I remove curlies and mix.

Answer 10

V, (削除) 28, 26, 25 (削除ここまで), 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

• user70974: This is competing. You may remove the title remark.
• Conor O'Brien: It's useful for those who weren't aware of the new meta, such as myself

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.

• Emigna: You could omit the < as one consistent leading space is okay.
• Adnan: A¹¡н«ðâƶāú should work for 10 bytes
• Erik the Outgolfer: @Adnan I think that ¹¡ will make it not work...oh so that's why there's a « in there. :p

Answer 13

R, (削除) 94 (削除ここまで) 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')
 }
}

• Giuseppe: 88 bytes : returning an anonymous function is fine, you can get rid of the braces since f is a one-liner, and using match instead of which saves a byte.
• Giuseppe: 71 bytes
• Giuseppe: 68 bytes taking input from stdin.

Answer 14

Haskell, (削除) 52 (削除ここまで) 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!

• jferard: 49 bytes:f k=[tail$[" ",s:" "]>>=(['A'..s]>>)|s<-['A'..k]]
• nimi: @jferard: Thanks a lot. Rereading the challenge I noticed that a leading space per line is allowed, so we don't need the tail$.

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, (削除) 15 (削除ここまで) (削除) 14 (削除ここまで) 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

• Erik the Outgolfer: It looks like we handled it a bit differently :D
• Emigna: @EriktheOutgolfer: We did it quite similarly, but your very nice idea to append a space before lifting, removing the need for the join made yours shorter. I hadn't read that leading/trailing spaces nor output as list was okay, so that'll hopefully teach me to read the whole challenge before implementing :P
• Erik the Outgolfer: tl;dr: vectorization :p
• Adnan: A¹¡н« instead of ADIk>£ should work
• Emigna: @Adnan: Thanks! I did have A¹¡н but didn't consider « to get the last letter so it wasn't good enough :P

Answer 17

APL (Dyalog Unicode), 22 bytes^SBCS

⍕⍪⊢∘⊂2,円.↑⍉⍴⍨⌸⎕a↑⍨⎕a⍳⍞

Try it online!

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

Answer 18

QBasic, (削除) 79 (削除ここまで) (削除) 74 (削除ここまで) 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.

• Taylor Raine: As it turns out you can use the INPUT$(1) command as a direct replacement for the variable z$ for a delta of -2 bytes
• DLosc: @TaylorScott Good idea, thanks!

Answer 19

Japt -R, (削除) 24 (削除ここまで) (削除) 23 (削除ここまで) (削除) 17 (削除ここまで) 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

×ばつ+§αι +ι1↘

Try it online!

• totallyhuman: Nah, you can't let 05AB1E beat Charcoal... :P
• Erik the Outgolfer: @totallyhuman the revenge :p
• Neil: Sadly arbitrary leading whitespace isn't allowed otherwise E...·?θ+× κ⪫× κι would do the job in 14 bytes.
• Erik the Outgolfer: @Neil One leading whitespace is allowed, but I'm not sure how ? got in there. It should be A instead I think. Oh wait, ohhhhh I see what you mean.

Answer 21

Braingolf, 65 bytes

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

Try it online!

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, (削除) 102 (削除ここまで) 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ドル

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ドル

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:

×ばつ ×ばつ 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.

• Dave: One of my favorite things about Pyth is writing an answer and finding that someone wrote the same answer, character for character. It hits that Python "there is a best answer" spot perfectly!
• Mr. Xcoder: @pizzakingme Yeah, I wonder if I can do better
• Dave: the space addition feels wrong, I think better is possible
• Mr. Xcoder: @pizzakingme I could get .e+*kdjd*bhk<GhxG as 17 bytes as well
• Dave: 16 bytes: .e+*kd*+bdhkhcGQ

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!

• Drise: I know there has to be a bunch of golfing things to do, but so far, that's the smallest I've gotten.