Create an ASCII line, given a length

Question

Information

Create a diagonal line given its length (let’s call the variable, say, \$n\$ where \$n > 0\$)

• The diagonal line starts from the top left and goes to the bottom right.
• You must use the ASCII character \ for the line.
• The input number can be given from STDIN or if your program doesn’t support that, use a hardcoded value in your code or pass it as an argument while running the program.
• For padding, only use the space character 0x20
• Trailing spaces and/or newlines are allowed.
• The length of the line is the non whitespace characters

Here is an example program (59 bytes):

n = int(input())
for i in range(n):
  print(' ' * i + '\\')

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Example:

Input: 4
Output
\
 \
  \
   \

Rules

• Use standard I/O when possible.
• Standard loopholes are forbidden.
• This is code golf, so the shortest answer in bytes wins.
• Please explain the code that you wrote.

Answer 1

Canvas, 1 byte

Better tool for the job ;)

＼

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Given an integer, this draws a diagonal of that string. If you pass a string instead, this prints the string along the diagonal. There is matching anti-diagonal builtin ／ as well.

Answer 2

Charcoal, 2 bytes

↖Ｎ

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right tool for the job

Answer 3

APL (Dyalog Unicode), 9 bytes (SBCS)

Anonymous tacit prefix function. Returns a list of string, as per meta consensus.

'\'↑⍨¨-∘⍳

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∘⍳ indices one through \$n\$, then:

 - negate those

¨ for each:

 ↑⍨ take (when negative: from the rear) that many characters (padding with spaces) from:

  '\' the backslash character

Answer 4

Jelly, 7 bytes

=þị⁾\ Y

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Ḷ⁶ẋp”\Y

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How they work

=þị⁾\ Y - Main link. Takes N on the left
=þ      - Yield the identity matrix of size N
  ị⁾\   - Index into "\ ", replacing 1 with "\" and 0 with " "
      Y - Join by newlines

Ḷ⁶ẋp”\Y - Main link. Takes N on the left
Ḷ       - Range [0, ..., N-1]
 ⁶ẋ     - Repeat that many spaces for each
   p”\  - Append "\" to each
      Y - Join by newlines

Answer 5

Japt -R, 5 bytes

õ!ù'\

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õ!ù'\     :Implicit input of integer
õ         :Range [1,input]
 !ù'\     :For each, left pad "\" to that length with spaces
          :Implicit output joined with newlines

Japt -mR, 5 bytes

'\iUç

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'\iUç     :Implicit map of each U in the range [0,input)
'\i       :Prepend to "\"
   Uç     :  Space repeated U times
          :Implicit output joined with newlines

Answer 6

51AC8, 10 bytes

R[\ ×\\+t]

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-2 bytes due to an update.

-7 bytes due to an update introducing for_each loops and range.

-1 byte online interpreter and implicit input.

Explanation

       # Implicit Input (STDIN) and push to stack
R      # Range from 0 to input (exclusive)
[      # Start for each
  \    # Push ' ' to the stack
  ×    # Multiply the top 2 elements on the stack
  \\   # Push '\'
  +    # Add top 2 elements
  t    # Pop and print top of stack
]      # End of while loop

Answer 7

Python 2, 37 bytes

x='\\'
exec'print x;x=" "+x;'*input()

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Answer 8

C (clang), 37 bytes

f(n){printf("%*c\n",n--,92,n&&f(n));}

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---

C (gcc), 39 bytes

A recursive version suggested by @att.

f(n){--n&&f(n);printf("%*c\n",n+1,92);}

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---

C (gcc), 44 bytes

i;f(n){for(i=0;i++<n;)printf("%*c\n",i,92);}

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Answer 9

Dyalog APL, 16 14 bytes

Solution - Takes in number of lines as input from user, and returns a string of diagonal line.

' \'[1+∘.=⍨⍳⎕]

Explanation

⎕            ⍝ ⎕ takes input from the user (number of lines)
             ⍝ In the below explanation, I have assumed ⎕ = 9 as input
⍳⎕            ⍝ 1 to 9 : [1,2,3,4,5,6,7,8,9]
∘.=          ⍝ Outer Product with Equality
⍨            ⍝ Apply a function with same argument on both sides
∘.=⍨⍳⎕       ⍝ ∘.=⍨ function applied to array ⍳⎕ = [1,2..9]
             ⍝ This is same as (⍳9) ∘.= (⍳9), which produces Identity Matrix of size 9
1+∘.=⍨⍳⎕     ⍝ Add 1 to each element of previous matrix (since APL uses 1-based index)
' \'[1+∘.=⍨⍳⎕] ⍝ From the string ' \', select characters specified by indices in 1+∘.=⍨⍳⎕

Answer 10

brainfuck, 113 bytes

,>>+++++++[<+++++++++++++>-]<+>++++++++++>>++++[<++++++++>-]<<<<[>>>>[->+>+<<]>[-<+>]>[<<<.>>>-]<<<<<.>.>>+<<<<-]

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First time poster. This was a fun exercise! Please provide criticism, I pretty much went in cold when writing this.

, how long the line should be via char code
>

initialize cell 1 with "\"
>+++++++[<+++++++++++++>-]<+
> 

initialize cell 2 with "\n"
++++++++++
>

initialize cell 3 with " "; go back to beginning
>++++[<+++++>-]<
<<<

start loop at cell 0
[
    >>>> go to cell 4
    [
        ->+>+<< copy the pad value to cells 5 and 6
    ]
    
    > now we move cell 5 to cell 4
    [
        -<+> cell 4 keeps track how much padding we'll need for our next iteration
    ]
    >

    cell 6 keeps track of how many spaces we need to print currently
    [
        <<<  go to space char
        .    print it
        >>>- decrease counter
    ]

    <<<<< move to line char
    .>.   print line and newline
    >>+   move to cell 4 and increase our padding by 1
    <<<<- back to cell 0; subtract line counter
]

Answer 11

Jelly, 7 bytes

Ṭ€ị⁾\ Y

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Working on golfing. This is longer than I remember it being possible. The JHT exercise allows other characters so I can't get this to 5 bytes because of that :/

Ṭ€ị⁾\ Y    Main Link
 €         For each (implicit range)
Ṭ          Generate a boolean list with 1s at the indices
  ị        Index that into
   ⁾\      "\ "
      Y    and join on newlines

Answer 12

J, 10 bytes

' \'{~=@i.

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Answer 13

C (clang), 90 77 60 bytes

i;main(n){for(scanf("%i",&n);i<n;printf("%*s\\\n",i++,""));}

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My first work without int in it while still using it. I'm doing better now, aren't I?

Thanks to att for golfing 13 bytes. Thanks to ceilingcat for golfing 17 bytes.

Answer 14

convey, 46 bytes

[0>>,+1
   v"^
{,"=@#]}
 >^}"~v#'\\'
' '!""~/}

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Visualization (i use '_' instead of space because the gif doesnt show the space char if i use it, but in the official page the output works whit spaces):

Answer 15

Vyxal M, 7 bytes

(nI\\+,

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Explanation:

(  # range from 0 to implict input
  n  # loop variable
   I  # push that many spaces
    \\  # backslash literal
      +  # concatenate the spaces with the backslash
       ,  # print

Answer 16

JavaScript (ES6), 33 bytes

f=(n,s=`\\
`)=>--n?s+f(n,' '+s):s

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Answer 17

MATLAB/Octave, 32 31 bytes

-1 byte thanks to Luis Mendo

disp([60*eye(input(''))+32,''])

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Reads the length from standard input, writes to standard output.
Makes use of identity matrix eye(x).

---

Alternatively, using function input/output, 22 21 bytes:

@(x)[60*eye(x)+32,'']

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Anonymous function, outputs character array.

Answer 18

Stax, 3 bytes

■♦9

Run and debug it

Explanation

m'\)
m    map 1..n and print with newlines
 '\) pad \ on the left with spaces to given length

Answer 19

05AB1E, 4 bytes

'\3Λ

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Using the input as length, draw \ in direction 3 (down-right) with the canvas builtin Λ. See Kevin's tip for details on how the canvas works

---

6 bytes without the canvas builtin:

'\ILj»

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For each number in the range IL == [1..input], pad the string "\" with leading spaces to this length (j). » joins the results by newlines.

Another 6 bytes solution suggested by Kevin Cruijssen:

L<'\ú»

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For each number in the range L< == [0..input-1], pad the string "\" with that many leading spaces.

Answer 20

Python 3.8 (pre-release), 46 bytes

for i in range(int(input())):print(' '*i+'\\')

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Answer 21

Vyxal jṀ, 4 bytes

ƛ\\꘍

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Flags go brrr

ƛ\\꘍   Full Program
ƛ      For each (implicity loops from 0 to n - 1)
 \\    push '\'
   ꘍   prepend x spaces to '\'

Ṁ is equivalent to mM, which makes implicit range start at 0 instead of 1 and end at n - 1 instead of n.

j joins the top of the stack on newlines at the end.

Answer 22

Red, 30 bytes

repeat i n[print pad/left"\"i]

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Answer 23

Java, 56 bytes

n->{for(var s="\\";n-->0;s=" "+s)System.out.println(s);}

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Answer 24

CJam, 10 bytes

ri{S*'\N}%

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Explanation

r             e# Read input
 i            e# Evaluate as an integer, n
  {     }%    e# Do the following for each k in [0 1 ... n-1]
              e# Push k (implicit)
   S          e# Push space
    *         e# Repeat. Gives a string with k spaces
     '\       e# Push character "\"
       N      e# Push newline
              e# Output the stack (implicit)

Answer 25

R, 35 bytes

cat(sep="\\
",strrep(" ",0:scan()))

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Answer 26

R, 42, 39 bytes

• -3 bytes thanks to @Dominic van Essen

write(strrep("\\",diag(x<-scan())),1,x)

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Explanation:

• take x from standard input,
• create a diagonal matrix of size x
• repeat the character '\' one time for each 1 of the matrix and 0-times for each 0 (= empty string)
• print the matrix separating each character with a space

Answer 27

PHP, 58 57 bytes

for($i=0;$i<$argv[1];$i++)echo str_repeat(' ',$i)."\\\n";

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This is my first golf, so feel free to mention anything I can do to improve this!

Answer 28

Factor, 40 bytes

[ iota [ [ bl ] times "\\"print ] each ]

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Answer 29

Perl 5, 34 bytes

s//\\/;$==<>;s// / while(say,$=--)

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This should be run from the command line like perl -E 's//\\/;$==<>;s// / while(say,$=--)' to activate the say feature without adding any bytes.

Ungolfed:

$_='\\'; #Set the default variable $_ to a single backslash
$==<>; #Take input into $=. This variable converts the input to an integer
while($=--){ #Decrement $= and loop
    say; #Prints $_ and a newline
    $_=" $_"; #Adds a space to the start of $_
}

Uses s// / as shorthand for $_=" $_" (i.e. to prepend a space to $_). Putting say into the while loop lets us drop the brackets from the loop body.

Answer 30

Ruby, 41 bytes

puts Array.new(gets.to_i){|i|(' '*i+'\\')}

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