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.

• zoomlogo: This was on Sandbox for a couple of days :)
• Wezl: Does the explanation count towards the byte count :?
• zoomlogo: The explanation is only for how the program works
• Luis Mendo: I suggest removing the rule "Use Standard I/O when possible". We have well-accepted default rules for I/O, and it would be unfair to force the use of standard I/O just because it is possible for a given language
• user: I'd suggest not accepting an answer (or at least not accepting one so quickly) in the future, as it may discourage others from answering.

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.

• hyperneutrino: lol, wow. definitely the perfect tool to pick :p
• Razetime: 13 hours too late for this :p
• hakr14: @Razetime 5 minutes too late to comment this...

Answer 2

Charcoal, 2 bytes

↖N

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right tool for the job

• caird coinheringaahing: Also 2 bytes

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[\ ×ばつ\\+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
 ×ばつ # 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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• att: 39 bytes
• Arnauld: @att Nice. That leads to a 37-byte version with clang. Undefined behavior for the win! ;-)

Answer 9

Dyalog APL, (削除) 16 (削除ここまで) 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+∘.=⍨⍳⎕

• ovs: ⎕ actually reads from the input section on TIO, but the way the program is run it doesn't implicitly output, you would need to prepend ⎕← to get output. The way to "enable" implicit output is to wrap the program into a tradfn and call that: Try it online!
• Sohang Chopra: @ovs How exactly is a tradfn different from a normal function definition? And how do you "enable" implicit I/O in tryapl.org (or, if this is not possible from the site, from Dyalog APL Windows Editor) ?
• ovs: Oh sorry I misread your post, tryapl.org indeed does not support ⎕. If you want to add a link for others to try this online, you could use the TIO one I sent above. I don't have Windows but I would assume that you can run ' \'[1+∘.=⍨⍳⎕] and then enter the number (like this). And tradfn is short for traditional function

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
]

• rydwolf: Welcome to Code Golf, and nice answer!

Answer 11

Jelly, 7 bytes

Ṭ€ị)\ Y

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(削除) Working on golfing. This is longer than I remember it being possible. (削除ここまで) 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

• zoomlogo: How did you create the answer so fast?? I think you guys have some sort of unicode keyboard to enter theses characters very quickly :P
• hyperneutrino: @MaanasB I have the wiki pages bookmarked and then I just copy-paste, lol. This is a standard exercise from the Jelly Hyper-Training room and it's a pretty simple challenge (not that that's bad, of course!)
• Shaggy: @MaanasB, I have (almost) all of the characters Japt uses on my phone's keyboard.
• Wezl: :/ two byte character literals. I'm disappointed in you, jelly :P
• hyperneutrino: @Wzl ? (filler filler)

Answer 12

J, 10 bytes

' \'{~=@i.

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Answer 13

R, 35 bytes

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

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Answer 14

C (clang), (削除) 90 (削除ここまで) (削除) 77 (削除ここまで) 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.

• att: -13 using for instead of while
• ceilingcat: 58 bytes

Answer 15

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):

enter image description here

Answer 16

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 17

JavaScript (ES6), 33 bytes

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

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Answer 18

R, (削除) 42 (削除ここまで), 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

• Dominic van Essen: 39 bytes using strrep... but I've found another approach that's still shorter (so far)...
• digEmAll: @DominicvanEssen Thanks! updated

Answer 19

MATLAB/Octave, (削除) 32 (削除ここまで) 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, (削除) 22 (削除ここまで) 21 bytes:

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

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Anonymous function, outputs character array.

Answer 20

Stax, 3 bytes

■しかく♦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 21

05AB1E, 4 bytes

'3円Λ

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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.

• Makonede: n o o o friggin ninjas
• Kevin Cruijssen: Alternative 6-byter using ú: ݨ'\ú»/L<'\ú».
• ovs: @KevinCruijssen thanks, added the second suggestion. It would be really nice if j would automatically swap arguments for integer lists as well.

Answer 22

Kotlin, 56 Bytes

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fun d(a:Int){var t="";repeat(a){println(t+'\\');t+=" "}}

ungolfed version
I think this code is obvious enough

fun d(a:Int)
{
 var t = ""
 repeat(a)
 {
 println(t + '\\')
 t += " "
 }
}

• zoomlogo: the `\`s are spaced apart :/
• zoomlogo: And you can use the header and footer on TIO like this: Try it online!
• random person: @PyGamer0 wait, the spaces are meant to incerment by 1 and not 2? well i can fix that, tomorrow. thx btw
• random person: It's been more than a month but I finally fixed it. @PyGamer0 Also thanks for tip

Answer 23

Nibbles, (削除) 5 (削除ここまで) 4 bytes (8 nibbles)

-2 nibbles thanks to a hint from Darren Smith

$&" "$"\\"

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Explanation

$&" "$"\\"
$ Input number
 (Implicit) Map over range from 1 to that number:
 & Left-justify
 "\\" string containing a backslash
 $ to a width given by the function argument
 " " by padding with spaces
 Output each element of that list on a separate line (implicit)

Answer 24

Python 3.8 (pre-release), 46 bytes

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

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• avarice: you should not answer your own question so soon
• zoomlogo: welp sorry didnt know that

Answer 25

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 26

Red, 30 bytes

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

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Answer 27

Java, 56 bytes

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

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Answer 28

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 29

PHP, (削除) 58 (削除ここまで) 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!

• caird coinheringaahing: Welcome to Code Golf, and nice first answer! Be sure to check out our Tips for golfing in PHP page for ways you can golf your program. Note that assuming the input is saved in a variable (e.g. $n) is not an acceptable method of input. Instead, you should take input via command line arguments, as a function argument or via STDIN
• SlamJammington: @cairdcoinheringaahing Thanks! I'll update it with a new version that takes input
• dingledooper: I'm not a PHP expert, but I can help improve your answer to 49 bytes.
• Sisyphus: ...and down to 35 bytes: Try it online!

Answer 30

Factor, 40 bytes

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

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