Create a percent sign

Question

Given an integer n ≥ 1, output a 2D representation^† of a percent sign of width n. The construction goes as follows:

Create an n by n matrix (or list of lists) filled with zeroes.
Insert ones in the top-left and bottom-right corners.
Place ones on the diagonal from the bottom-left to the top-right.

For input n = 4, this construction would look like:

1. 4x4 matrix of 0s 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2. 1s in TL and BR corners 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 3. 1s across BL-TR diagonal 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1

This is a code-golf, so the shortest program in bytes wins.

^† I use a matrix of 1s and 0s, but it is also acceptable to use a string of any non-whitespace character and spaces. So, the example above could look like:

# # # # # #

or

# # # # # #

Test cases

n output 1 1 2 1 1 1 1 3 1 0 1 0 1 0 1 0 1 4 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 10 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1

Final note

Adding an explanation would be greatly appreciated.

@Cowsquack I'd say no. You're receiving the width, not an index. — Conor O'Brien
– Conor O'Brien, Commented Jul 21, 2017 at 17:44
@xnor Yes; list of lists and matrix are synonymous in my post. I'll add that to the question — Conor O'Brien
– Conor O'Brien, Commented Jul 21, 2017 at 18:15

Kamil Drakari · Accepted Answer · 2017-08-01 15:21:28Z

C# (.NET Core), 65 bytes

w=>{var l=new int[w*w];for(int i=0;i<w*w;i+=w-1)l[i]=1;return l;}

Try it online!

The algorithm is significantly distinct from the other C# answer, so I decided to post it separately rather than as an improvement. Inspired by the top rated Jelly answer actually, I was doing something slightly less compact before. The output is a linear array, so would require some logic to wrap it into a 2D outside the method as-is. An alternate version requires 6 additional bytes to output as a true 2D array:

w=>{var l=new int[w,w];for(int i=0;i<w*w;i+=w-1)l[i/w,i%w]=1;return l;}

I also have an interesting non-competing version.

using System.Linq;w=>new int[w*w].Select((_,i)=>i%(w-1)<1)

This ends up with almost the right output, resulting in an IEnumerable<bool> with true/false instead of 1/0, and it's a linear rather than 2D structure, and although not needed for that exact line of code, using System.Collections.Generic is necessary to do anything useful with the output. Like I said, it's very close to being valid but not quite.

For the second using a ternary as in ?1:0 works and I believe an array of the result should be fine. The collections using also isn't necessary for that code. — TheLethalCoder
– TheLethalCoder, Commented Aug 1, 2017 at 15:24
For the first, would setting w*w to a variable and moving the int declaration out of the loop save you anything? — TheLethalCoder
– TheLethalCoder, Commented Aug 1, 2017 at 15:25
@TheLethalCoder Replacing the two instances of w*w with a single character variable saves 4 bytes, moving int i=0 outside the loop requires a semicolon which costs 1 byte, and then adding ,s=w*w to the declaration costs 6 bytes, so it actually nets +3 bytes. — Kamil Drakari
– Kamil Drakari, Commented Aug 1, 2017 at 15:36
You should use the byte count of the full 2D-representation solution. The array returned by the shorter solution would at least need to include some sort of delimiter to be valid. — Jakob
– Jakob, Commented Aug 12, 2017 at 3:37

Asleepace · Accepted Answer · 2017-08-01 18:07:12Z

C, 216 212 186 155 145 Bytes

Just as a function that takes a matrix as input

f(int i,int **m){for(int a=0;a<i;a++){for(int b=0;b<i;b++){m[a][b]=((a+b+1==i)||(!a&&!b)||(a==i-1&&b==i-1))?1:0;printf("%d ",m[a][b]);}puts();}}

6 Bytes thanks to Conor O'Brien!

4 Bytes thanks to Zacharý!

Old Answer

main(int i){int**m=malloc(8*i);for(int a=0;a<i;a++){m[a]=malloc(4*i);for(int b=0;b<i;b++){m[a][b]=((a+b+1==i)||(a==0&&b==0)||(a==i-1&&b==i-1))?1:0;printf("%d ",m[a][b]);}printf("\n");}}

Instead of taking an array of arguments in the main function, it uses the length of arguments instead so the input for a 4x4 matrix would be:

Old Answer

main(int c,char **v){int i=atoi(v[1]);int**m=malloc(8*i);for(int a=0;a<i;a++){m[a]=malloc(4*i);for(int b=0;b<i;b++){m[a][b]=((a+b+1==i)||(a==0&&b==0)||(a==i-1&&b==i-1))?1:0;printf("%d ",m[a][b]);}printf("\n");}}

If only I could get rid of of those mallocs, I know C is not a great golfing language, but whatever!

Compiled with GCC on macOS Sierra.

Ungolfed

main(int i) { int **m = malloc(8 * i); // Create n*n matrix for(int a=0; a<i; a++) { // Iterate through rows m[a] = malloc(4 * i); // Allocate rows for(int b=0; b<i; b++) { // Iteratre columns // Add a 1 to cell if its start or finish, or diagnol m[a][b]=((a+b+1==i)||(a==0&&b==0)||(a==i-1&&b==i-1))?1:0; printf("%d ",m[a][b]); // Print cell } printf("\n"); // Print row }

Usage

Awesome thanks I just got start golfing, thanks for the help! — Asleepace
– Asleepace, Commented Aug 1, 2017 at 6:11
If you change your IO method to accepting a parameter as input, then outputting to STDOUT, then I think f(i){int a,b;for(a=0;a<i;a++){for(b=0;b<i;b++)printf("%d ",a+b+1==i||!a&&!b||a==i-1&&b==i-1);printf("\n");}} works. — Adalynn
– Adalynn, Commented Aug 1, 2017 at 14:33
Okay, is it okay if I post my solution separately due to the differing IO method? — Adalynn
– Adalynn, Commented Aug 1, 2017 at 18:27

Community · Accepted Answer · 2020-06-17 09:04:33Z

Google Sheets, 58 bytes

=If(A1=1,1,RegexReplace(Rept(10^(A1-2),A1+1)&1,"(.{"&A1&"})","$1 "))

Input is in A1.

Explanation:

10^(A1-2) generates a one followed by n-1 zeroes.
Rept(10^(A1-2),A1+1)&1 generates n+1 copies of that sequence with an extra one at the end. For n=5 as an example, that string is 1000100010001000100010001.
RegexReplace(~,"(.{"&A1&"})","$1\n") replaces every grouping of n characters with itself plus a line break. (In the actual formula, I use a literal line break rather than the escaped \n.)
This breaks on n=1 because 10^-1 = 0.1 so the string is 0.10.11. The If at the beginning escapes that special case.

Results:

_{^{^{I took the screenshot of exactly those cells and the image turned out to be 323 x 232 pixels. I think that's neato.}}}

Community · Accepted Answer · 2020-06-17 09:04:33Z

Mathematica, 59 56 48 bytes

(x=Sort@IdentityMatrix@#;x[[1,1]]=x[[#,#]]=1;x)&

The identity matrix has a diagonal of 1s, but it's going the wrong way. Sorting the rows fixes this. Then we set the corners to be 1 as well, and return the matrix.

You can test this out in the Wolfram Cloud sandbox by pasting code like the following and clicking "Evaluate cell" or hitting Shift+Enter or the numpad Enter:

(x=Sort@IdentityMatrix@#;x[[1,1]]=x[[#,#]]=1;x)&@5//ArrayPlot

Longer solutions

SparseArray[#->1&/@{Band[{1,#},{#,1},{1,-1}],{1,1},{#,#}}]&

The #->1& is an anonymous function that associates the input with 1, and the Band represents the coordinates from {1,#} to {#,1} going in steps of {1,-1}.

f[n_]:=Boole[#==#2==1||#==#2==n||#+#2==n+1]&~Array~{n,n}

This builds an n by n array where the values are 1 or 0 depending on the truth of "both indices are 1 or both indices are n or both indices sum to n+1".

emanresu A · Accepted Answer · 2021-08-17 23:31:33Z

Vyxal `r`, 6 bytes

‹?²ʁḊẇ

Try it Online!

‹ # n-1 ?²ʁ # 0...n^2 Ḋ # Foreach, is it divisible by (n-1)? ẇ # Split into chunks of (implicit input) length.

chunes · Accepted Answer · 2024-03-22 10:11:04Z

2

Uiua ^SBCS, 10 bytes

↯▽2:⊂1↘2⊚.

Try it!

Port of Adalynn's APL answer.

↯▽2:⊂1↘2⊚. . # duplicate ⊚ # list of n zeros ↘2 # drop first two ⊂1 # prepend one ↯▽2: # reshape to nxn

answered Mar 22, 2024 at 10:11

chunes

27.8k3 gold badges32 silver badges55 bronze badges

\$\begingroup\$ TIL scalar where, nice \$\endgroup\$

noodle person
– noodle person

2024-03-25 12:21:06 +00:00
Commented Mar 25, 2024 at 12:21
1

\$\begingroup\$ Alternate 10: ↯:⊂1↘2⊃⊚⊟. \$\endgroup\$

noodle person
– noodle person

2024-03-25 12:28:25 +00:00
Commented Mar 25, 2024 at 12:28

Add a comment |

ovs · Accepted Answer · 2017-07-21 17:50:20Z

1

Retina, 44 bytes

\d+ $* $ # +` ( *)#( *)$ $&¶$1#$2 ^ | $ #

Try it online!

answered Jul 21, 2017 at 17:50

ovs

61.2k3 gold badges49 silver badges164 bronze badges

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Neil · Accepted Answer · 2017-07-21 19:11:31Z

Retina, 24 bytes

.+ $* . $'#$`¶ ^ | ¶$ #

Try it online! Explanation: The second line ends in a space, so the first stage converts the input into a row of spaces. The second stage then replaces each space in the row with a # in turn, collecting the resulting lines together. The final stage then adds the corner #s.

JAD · Accepted Answer · 2017-07-21 20:50:24Z

R (+pryr), 36 bytes

pryr::f(matrix(c(1,rep(0,n-1)),n,n))

Evaluates to the function:

function (n) matrix(c(1, rep(0, n - 1)), n, n)

Which is a port from this APL answer.

ricdesi · Accepted Answer · 2017-07-21 20:53:23Z

PHP, 131 bytes

<?$m=$n=0;while($m<$argv[1]){while($n<$argv[1]){echo($m==$n&&(!$m||$m==$argv[1]-1)||$m+$n==$argv[1]-1)*1;$n++;}echo"\n";$m++;$n=0;}

Exploded view

<? $m = $n = 0; while ($m < $argv[1]) { while ($n < $argv[1]) { echo ($m == $n && (!$m || $m == $argv[1]-1) || $m + $n == $argv[1]-1) * 1; $n++; } echo "\n"; $m++; $n = 0; }

Not my best work, I'm certain I can golf this down.

Add $a=$argv[1]; at the beginning and replace all $argv[1] with $a to save several bytes. — manassehkatz-Moving 2 Codidact
– manassehkatz-Moving 2 Codidact, Commented Jul 23, 2017 at 4:15
Also take $n= out of the top 0 assignment and move $n=0; from the end of the outer loop to the beginning to save another 3 bytes. — manassehkatz-Moving 2 Codidact
– manassehkatz-Moving 2 Codidact, Commented Jul 23, 2017 at 5:36

Sherlock9 · Accepted Answer · 2017-07-30 20:09:22Z

Actually, 14 18 bytes

A simple algorithm.

Edit: Fixing a bug for n == 1

;;D╤$0D@H@u*'1@+╪i

Ungolfing

 Implicit input: n ;; Duplicate n twice. D╤$ Push str(10**(n-1)) 0D@H Push str(10**(n-1))[:-1] @u* Push str * (n+1) '1@+ Append a "1" ╪ Split into chunks of length n i Flatten this list onto the stack Implicit print

Try it online!

Business Cat · Accepted Answer · 2017-08-02 13:49:34Z

Gaia, 7 bytes

s…@(Ė¦/

Try it online!

Explanation

s Square n … Get the range from 0 to n^2-1 @( Push n-1 Ė¦ For each number in the range, check if n-1 divides it / Split into slices of size n

Jaggler3 · Accepted Answer · 2017-08-12 06:50:56Z

WC, 92 bytes

;>_0|$-$-!!_1|;>@5|$''[<]!!$!_1|;>(?##@2|;>@5|$''[<<<]!!$!_1|?$-[>>>];</#)*$?!!_1|[>]!!$!_1|

Input

Artifact 0: a number ex. 5

Artifact 1: a string ex. #

Output

# # # # # # #

Explanation

;>_0| Create variable set to artifact 0 $-$- Decrement twice !!_1| Print artifact 1 with no newline ;>@5| Create variable set to global 5 (the space character) $''[<] Repeat variable times the previous variable !!$ Print with no newline !_1| Print artifact 1 with newline ;>( Create variable as function ? Reset variable index to 0 ##@_2| Start if-not statement, runs if not global 2 (zero) ;>@5| Create variable set to global 5 (the space character) $''[<<<] Repeat variable times index-3 (first variable) !!$ Print with no newline !_1| Print artifact 1 with newline ?$- Reset index to 0 and decrement [>>>] Move index up 3 ;< Delete at index / Restart context # End statement ) End function *$? Call function and reset index !!_1| Print artifact 1 with no newline [>]!!$ Move index up 1 and print with no newline !_1| Print artifact 1 with newline

NOTE: Do NOT set artifact 1 to 1, it will freeze. Works for n > 1

Try it online!

Community · Accepted Answer · 2020-06-17 09:04:33Z

Perl 5, 66 bytes

$n=pop;$_='#';for$x(0..$n){$_.=$"x($n-2).'#'};s/(.{$n})/$1\n/g;say

Takes input as first command line argument.

Builds up a string of length n^2 with # at the proper spots, then inserts newlines at the right places.

0xffcourse · Accepted Answer · 2017-08-12 15:49:17Z

1

Python 3, 71 67 65 76 bytes

lambda n:n>1and''.join(' #'[i%~-n<1]+'\n'*(-~i%n<1)for i in range(n*n))or'#'

Try it online!

edited Aug 12, 2017 at 15:49

answered Jul 21, 2017 at 18:02

0xffcourse

2,7993 gold badges15 silver badges27 bronze badges

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Jakob · Accepted Answer · 2017-08-14 17:47:38Z

Java 8, 74 bytes

Essentially just a port of Kamil's second C# solution here.

n->{int g[][]=new int[n][n],i=0;for(;i<n*n;i+=n-1)g[i/n][i%n]=1;return g;}

Try It Online

LegionMammal978 · Accepted Answer · 2020-10-31 21:04:27Z

1

Husk, 9 bytes

´Ṫȯ¬%←¹+ŀ

Try it online! This function creates a matrix with indices from the range [0..n) and tests that their sum is divisible by n - 1.

answered Oct 31, 2020 at 21:04

LegionMammal978

18.2k4 gold badges25 silver badges58 bronze badges

\$\begingroup\$ Another 9 byte solution \$\endgroup\$

Razetime
– Razetime

2020-11-01 14:02:06 +00:00
Commented Nov 1, 2020 at 14:02

Add a comment |

JosiahRyanW · Accepted Answer · 2020-11-02 05:37:50Z

CJam, 18 bytes

qi__))'#*\((S**/N*

Try it online!

Joins n+2 hash characters together by n-2 spaces, then splits into n-length groups and joins by newline.

coltim · Accepted Answer · 2021-01-23 16:11:01Z

K (oK), 15 14 bytes

{(x,x)#1,2_&x}

Try it online!

Adapted from @Zacharý's APL answer.

2_&x generate x-2 copies of zero
1, prepend a one
(x,x) duplicate x
(...)#... reshape into a x-by-x matrix

Xcali · Accepted Answer · 2024-04-06 22:24:09Z

Perl 5, 67 57 + 1 (`-p`) = 58 bytes

$\=$_=10**$_/10+($_>1);for$i(2..y///c){say;s/.//;$_.=0}}{

Try it online!

Takes the input implicitly (-p). Convert that to 10 to the power of the input minus 1 and add one if the input is greater than one. Outputs that as a string, then removes first character and appends a 0, looping until it has output n-1 rows. For the last row, implicitly output the copy of the first row which has been stored in $\.

Stack Exchange Network

Create a percent sign

Test cases

Final note

50 Answers 50

C# (.NET Core), 65 bytes

C, 216 212 186 155 145 Bytes

Ungolfed

Usage

Google Sheets, 58 bytes

Mathematica, 59 56 48 bytes

Longer solutions

Vyxal `r`, 6 bytes

Uiua ^SBCS, 10 bytes

Retina, 44 bytes

Retina, 24 bytes

R (+pryr), 36 bytes

PHP, 131 bytes

Actually, 14 18 bytes

Gaia, 7 bytes

Explanation

WC, 92 bytes

Input

Output

Explanation

Perl 5, 66 bytes

Python 3, 71 67 65 76 bytes

Java 8, 74 bytes

Husk, 9 bytes

CJam, 18 bytes

K (oK), 15 14 bytes

Perl 5, 67 57 + 1 (`-p`) = 58 bytes

Linked

Hot Network Questions

Create a percent sign

Test cases

Final note

50 Answers 50

C# (.NET Core), 65 bytes

C, 216 212 186 155 145 Bytes

Ungolfed

Usage

Google Sheets, 58 bytes

Mathematica, 59 56 48 bytes

Longer solutions

Vyxal r, 6 bytes

Uiua SBCS, 10 bytes

Retina, 44 bytes

Retina, 24 bytes

R (+pryr), 36 bytes

PHP, 131 bytes

Actually, 14 18 bytes

Gaia, 7 bytes

Explanation

WC, 92 bytes

Input

Output

Explanation

Perl 5, 66 bytes

Python 3, 71 67 65 76 bytes

Java 8, 74 bytes

Husk, 9 bytes

CJam, 18 bytes

K (oK), 15 14 bytes

Perl 5, 67 57 + 1 (-p) = 58 bytes

Linked

Related

Hot Network Questions

Vyxal `r`, 6 bytes

Uiua ^SBCS, 10 bytes

Perl 5, 67 57 + 1 (`-p`) = 58 bytes