# Print N Squared

Write a program or function that takes in a non-negative integer N from stdin or as a function argument. It must print or return a string of a hollow ASCII-art square whose sides are each made with N copies of the number N.

### Specifically:

If N is 0, no copies of N are used, so there should be no output (or only a single trailing newline).

If N is 1, the output is:

1


If N is 2:

22
22


If N is 3:

333
3 3
333


If N is 4:

4444
4  4
4  4
4444


If N is 5:

55555
5   5
5   5
5   5
55555


The pattern continues for 6 through 9.

If N is 10, the output is:

10101010101010101010
10                10
10                10
10                10
10                10
10                10
10                10
10                10
10                10
10101010101010101010


Notice that this is not actually square. It is 10 rows tall but 20 columns wide because 10 is two characters long. This is intended. The point is that each side of the "square" contains N copies of N. So all inputs beyond 9 will technically be ASCII rectangles.

For example, if N is 23, the output is:

2323232323232323232323232323232323232323232323
23                                          23
23                                          23
23                                          23
23                                          23
23                                          23
23                                          23
23                                          23
23                                          23
23                                          23
23                                          23
23                                          23
23                                          23
23                                          23
23                                          23
23                                          23
23                                          23
23                                          23
23                                          23
23                                          23
23                                          23
23                                          23
2323232323232323232323232323232323232323232323

Here are Pastebins of the required outputs for 99, 100, 111, and 123 (they may look wrong in a browser but in a text editor they'll look correct). The output for 1000 is to large for Pastebin but it would have 1000 rows and 4000 columns. Numbers with 4 or more digits must work just like smaller numbers.

### Details:

• N must be written in the usual decimal number representation, with no + sign or other non-digits.
• The hollow area must only be filled with spaces.
• No lines should have leading or trailing spaces.
• A single newline after the squares' last line is optionally allowed.
• Languages written after this challenge was made are welcome, they just aren't eligible to win.
• The shortest code in bytes wins!
• The square for n=10 looks more square than for n=5. Hooray, non-square fonts! Feb 20, 2016 at 19:04
• May we take the integer as a string?
Mar 2, 2016 at 18:42
• @Nᴮᶻ Yes you may Mar 2, 2016 at 19:10

# MathGolf, 2825 19 bytes

░*k┴╜o\⌡{khí **k++p


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## Explanation

This was a fun challenge. Disclaimer: this language is younger than the challenge itself, but the methods used for this answer are not designed for this challenge in particular. I realised that I can save a byte for the 1-case, and by reducing the number of print statements.

░                     convert implicit input to string
*                    pop a, b : push(a*b)
┴                  check if equal to 1
╜                 else without if
o                print TOS without popping (handles the 1-case)
\               swap top elements
⌡              decrement twice
{             start block or arbitrary length
h           length of array/string without popping
í          get total number of iterations of for loop
space character
*        pop a, b : push(a*b)
*       pop a, b : push(a*b) (this results in (n-2)*numdigits(n)*" ")
+     pop a, b : push(a+b)
+    pop a, b : push(a+b)
p   print with newline

• @JoKing that added two bytes. I wanted to be able to use the "make each list element equal in length" operator, but I couldn't get it working as I wanted.
– maxb
Oct 5, 2018 at 11:35

## Pyth, 27 bytes

jsMmm?sqM*,dk,0tQQ*\ lQQQ


# 05AB1E, 3430 29 bytes

Code:

F¹}JDU,¹!#¹DÍF¹gFð}}¹J¹ÍF=}X,


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I didn't have some kind of fancy string multiplication function, but here is the submission with the function. It's something I added after the challenge and is therefore non-competing:

Non-competing version (26 bytes)

Code:

D×DU,¹¹Í¹g*ð×¹J¹ÍF=}¹1›iX,


Uses CP-1252 encoding.

# PHP 112 114120 bytes

<?php $z=$j=$argv[1];while($j){$i=(--$j&&$i)?$z.str_pad('',strlen($z)*($z-2)).$z:str_repeat($z,$z);echo"$i\n";}


Command line usage: php scriptname.php [n]

ideone demo

This golf uses str_repeat for the first and last row and str_pad for the rows in between.

## Ruby, 79 bytes

->n{s=n.to_s
puts s*n
$><<(s+" "*s.size*(a=n-2)+s+$/)*a if n>2
$><<s*n if n>1}  Some cases print a trailing line after the last line and some do not, but the question does not disallow this. # Dyalog APL, 41 bytes {1≥⍵:⍵⍴⍵⋄(' '≠⍕⍵/⍵)/⍕⍵⍪⍨⍵⍪⍵,⍵,⍨''⍴⍨2/⍵-2}  # Python 2, 73 characters def l(i):s=i;n='\n';l=i-2;b=s*i+n;print b+(s+' '*l*len(s)+s+n)*l+b*(i>1)  • I believe your n='\n'; optimization is costing you one character, not saving any. May 6, 2016 at 18:45 # Python 3.5, 101 135 bytes: (+34 since apparently an input of 1 should just output 1 and an input of 0 should output nothing) def y(g):g=str(g);i=len(g);[print(g*(int(g))+('\n'+g+' '*((int(g)*i)-(i*2))+g)*(int(g)-2)+'\n'+g*int(g))if int(g)>1 else print(g*int(g))]  Prints out all the correct values for any integer input, whether in string form or not. Sample Inputs and Outputs: Input: y(10) Output: 10101010101010101010 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10101010101010101010 Input: y(1) Output: 1 Input: y(2) Output: 22 22 Input: y(4) Output: 4444 4 4 4 4 4444  However, for triple digit numbers, it was just too big to fit on my monitor, so I hope that comes out correct if someone else tries it. I suspect it should since all 1 and 2 digit numbers come out correctly. # PHP, 86 Bytes for(;$i<$a=$argn;)echo str_pad($a>1?$a:"",($a-1)*strlen($a),$i++&&$i<$a?" ":$a)."$a ";  Try it online! # JS to ES6 compatibilized, 136 76 B function x(a){var c='';function Q(){for(var b=0;b<a;++b)c+=a}Q();c+='\n'; for(b=2;b<a;++b){c+=a;for(let A=2;A<a;++a)c+=' ';c+=a+'\n'}Q()}  Works way smaller: x=(a,c)=>{Q=(í,k)=>{for(;í<a;++í)c+=k}Q(0,a);c+='\n';Q(2,a+Q(2,' ')+a+'\n')}  Python 2,96 bytes s=raw_input() n=int(s) for i in range(n): if 0<i<n-1:print s+' '*(n-2)*len(s)+s else:print s*n  Python 3,94 bytes s=input() n=int(s) for i in range(n): if 0<i<n-1:print(s+' '*(n-2)*len(s)+s) else:print(s*n)  • You accidentally left a space after the assignment to n in both answers. Oct 5, 2018 at 18:27 # Vyxal, 20 bytes ẋṅ,⇩(L⁰‹*$S↲₴,)ċ[ẋṅ,


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## How?

ẋṅ,⇩(L⁰‹*$S↲₴,)ċ[ẋṅ, ẋ # Repeat the (implicit) input the (implicit) input number of times (returns a list) ṅ # Join by nothing , # Print with trailing newline ⇩( # Loop (implicit) input minus 2 times: L # Get the length of the (implicit) input ⁰‹ # Push the input minus 1 * # Multiply the length by that$           #  Swap to make (implicit) input at top
S          #  Convert the input to a string
↲         #  Pad the stringified input with leading spaces until its length is len(input) * (input - 1) calculated earlier
₴        #  Print this without a trailing newline
,       #  Print the (implicit) input with trailing newline
)      # Close loop
ċ[    # If the (implicit) input is not one:
ẋ   #  Repeat the (implicit) input the (implicit) input amount of times
ṅ  #  Join by nothing to make it a string
, #  Print with trailing newline


# Mathematica,116 bytes

Switch[#,0,"",1,1,_,#5<>#4[#<>#4[" ",StringLength@#*#3]<>#<>"\n",#3]<>#5&[##,#~#4~#2<>"\n"]&[ToString@#,#,#-2,Table]]&


Somewhat long, but oh well.

# Oracle SQL 11.2, 106105 115 bytes

SELECT RPAD(:1,(:1-1)*LENGTH(:1),DECODE(LEVEL,1,:1||'',:1,:1||'',' '))||:1 FROM DUAL WHERE:1>0 CONNECT BY:1>=LEVEL;


10 bytes added to manage 0

## Python 3, 75 characters

def q(n):s=str(n);m=n-2;print(s*n,*[s+" "*len(s)*m+s]*m,s*n*(n>1),sep="\n")

• Welcome to Programming Puzzles and Code Golf. This is a great first answer, however it would be even better if you added a code explanation and breakdown as well. May 6, 2016 at 19:23

# SmileBASIC, 89 bytes

INPUT N$N=VAL(N$)Q=N>1FOR I=1TO N?N$*!!N*G;" "*LEN(N$*(N-Q*2))*G;N$*(Q*G+N*!G)G=I<N-1NEXT  # Common Lisp, SBCL, 151 bytes (defun c(x)(if(< x 10)1(1+(c(/ x 10)))))(lambda(a)(format t"~:[~v{~a~:*~}~&~v@{~v<~a~;~a~>~4@*~&~}~*~v@{~a~:*~}~;1~]"(= a 1)a(,a)(- a 2)(*(c a)a)a a))  function for counting digits adjusted to CL from Joshua's answer here ### Ungolfed (defun c(x) (if(< x 10) 1 (1+ (c(/ x 10))))) ;counting digits (lambda(a) (format t"~:[~v{~a~:*~}~&~v@{~v<~a~;~a~>~4@*~&~}~*~v@{~a~:*~}~;1~]"(= a 1)a(,a)(- a 2)(*(c a)a)a a)) ;~[~] checks whether agument is equal 1 (if it is equal 1 then print out only "1") - without it we would print out 1\Newline 1 ;first loop: ~v{~a~:*~} - printing first line of N ;second loop: uses justification "~<~>" to output enough spaces between N's on sides ;third loop: -printing last line of N  ## QBIC, 61 58 bytes ;_LA|x=!A!~x=1|?A\Y=A+space$((x-2)*a)+A[x|Z=Z+A]?Z[x-2|?Y]


Explanation

;          Read A$from the cmd line _LA| Take the length of A$ and assign to a
x=!A!      Cast A$to int, assign to x ~x=1|?A If x == 1, quit printing just the 1 \Y=A Else, setup Y$ as the middle of the square; it starts as the literal input
+space$( Followed by X spaces (x-2)*a) where X is the length of the string x the value, minus start and end +A Followed by the input again [x| This FOR loop creates the top row Z=Z+A] By concatenating the input x times to itself and assigning it to Z$
?Z         Print the top row
[x-2|?Y]   Print the right amount of middle rows
And the bottom row (Z$) is implicitly printed at EOF.  • Non-competing maybe? May 6, 2017 at 10:19 # Lua, 101 bytes p,n=print,io.read()d,s=#n,n:rep(n)p(s)for i=3,n do p(n..(" "):rep(d*(n-2))..n)end p(n+0>1 and s or"")  Alternate 102 bytes: l,n="\n",io.read()d,s=#n,n:rep(n)print(s..l..(n..(" "):rep(d*(n-2))..n..l):rep(n-2)..(n+0>1 and s or""))  101 Readable: p,n=print,io.read() d,s=#n,n:rep(n) p(s) for i=3,n do p(n..(" "):rep(d*(n-2))..n) end p(n+0>1 and s or"")  Lua naturally has a small trick here by being able to convert a number as a string (e.g. "123") into a string or a number as needed based on context. It's not 100% intelligent though as you can see in my "ternary" statement at the end for handling the 0 and 1 cases- I had to use n+0 to coax it into a number before comparing it to 1. # Perl 5, 67+2=69 bytes Requires the flags -lp. $@=($,=$"=$_)-2;$,x=$,;s/./ /g;$"=$".$_ x$@.$".$/;$_=$,.$/.$"x$@.$,  Has all the length of a mainstream language, and the unreadability of a more esoteric language! # WC, 146 bytes ;>_0|;>_0|$-;>_0|;>=_0|[<]$'[>]$--[>]$--[>];>_0|$''_0|!$?#@3|//#;>(?[>]$-!!_0|;>@5|$''[<<<<]!!$?!$[>>>>>>];<?[>]##@3|/#)?##@10|[>>>>>]*$#?[>>>>]!$ Try it online! Ungolfed/commented: ;>_0|;>_0| var n, var c$-               decrement c
;>_0|;>=_0|      var i, var len = length(X)
[<]              move to i
$'[>] multply i by len$--[>]$--[>] i -= len (x2) ;>_0|$''_0|      var full = X repeated X times
!$print full ? reset index #@3| if n == 0 // terminate # end if ;>( new function ?[>] set index to 1$-!!_0|        decrement c and print it
;>@5|          var spaces
$''[<<<<] repeat i times !!$            print spaces
?              reset index
!$print n [>>>>>>] move to spaces ;< delete spaces var ?[>] set index to 1 ##@3| if c != 0 / restart context (this function) # end if ) end function ? reset index ##@10| if n != 2 (10th global) [>>>>>] set index to 5 *$             call the function
#                end if
?[>>>>]          set index to 4
!\$                print full

• When you compile Wasp, it becomes the Water Closet
– user96495
Aug 22, 2020 at 14:15

# APL(NARS), 69 chars, 138 bytes

{⍵≤1:⍕⍳⍵⋄f←{⊂∊⍺/⊂⍕⍵}⋄y←((⍴⊃x←f⍨⍵)-2×⍴r←⍕⍵)f' '⋄⊃x,((⊂∊r,y,r)/⍨⍵-2),x}


test:

  g←{⍵≤1:⍕⍳⍵⋄f←{⊂∊⍺/⊂⍕⍵}⋄y←((⍴⊃x←f⍨⍵)-2×⍴r←⍕⍵)f' '⋄⊃x,((⊂∊r,y,r)/⍨⍵-2),x}
⎕fmt   g¨0 1 2 3 11
┌5──────────────────────────────────────────┐
│┌0┐ ┌1┐ ┌2─┐ ┌3──┐ ┌22────────────────────┐│
││ │ │1│ 222│ 3333│ 11111111111111111111111││
│└¯┘ └─┘ │22│ │3 3│ 111                  11││
│        └──┘ │333│ │11                  11││
│             └───┘ │11                  11││
│                   │11                  11││
│                   │11                  11││
│                   │11                  11││
│                   │11                  11││
│                   │11                  11││
│                   │11                  11││
│                   │1111111111111111111111││
│                   └──────────────────────┘2
└∊──────────────────────────────────────────┘


# Pyth, 29 bytes

*zKszVSJ-K2p+z*J*lzdz)I>K1*zK


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Properly handles "1" case, even if it cost me 3 more characters to do so. Still new to Pyth, and there's some interesting stuff happening with that Pyth answer that uses all the joins.

*zKsz        #input auto-assigned to z as string, assign K to int(z), and print z*K
VSJ-K2       #set J to K-2, for N in range J
p+z*J*lzdz   #print with no newline: z + (" " * len(z)) * (K - 2), print z
)I>K1*zK     #close for loop and print z*K if K greater than 1


# Python 3, 78 bytes

N=input()
n=int(N)
m=n-2
b=N*n+"\n"
print(b+(N+" "*len(N)*m+N+"\n")*m+b*(n>1))


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I went back and forth over multiple approaches to this (even using exec() at one point, then ditching it because it was unnecessary), but I figured out that this is the shortest Python 3 approach.

# C# (.NET Core), 146 bytes

a=>{string b=a.ToString(),s="";for(int i=0,j,k;++i<=a;s+="\n")for(j=0;++j<=a;)if(i>1&i<a&j>1&j<a)for(k=0;k++<b.Length;)s+=" ";else s+=b;return s;}


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Ungolfed:

a => {
string b = a.ToString(), s = "";            // initialize b (saves 4 bytes) and s (return variable)
for(int i = 0, j, k; ++i <= a; s += "\n")   // for each row of the square
for(j = 0; ++j <= a;)                       // for each column of the square
if(i > 1 & i < a & j > 1 & j < a)           // if not an edge of the square
for(k = 0; k++ < b.Length;)                 // for each digit in a
s += " ";                                   // add a space
else                                        // if an edge of the square
s += b;                                     // add the input num
return s;                                   // output the full string


# Japt, 22 bytes


_hUçU)z3
NgV gV gV gV


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More competitive than I expected, though I wouldn't be surprised if Charcoal or something has a really short answer that just hasn't been found yet.

Explanation:


:Empty line preserves the input as U

_hUçU)z3        :Declare a function V taking an argument Z:
_h   )          : Set the first line of Z to
U           :  U as a string
Uç            :  Repeated U times
z3        : Rotate Z 90 degrees counterclockwise

NgV gV gV gV    :Main program
gV gV gV gV    : Apply V 4 times


It's necessary to rotate counterclockwise in V because a single-line array always ends up left-aligned when rotated, making clockwise rotations take an extra gV. The 1 extra byte for z3 instead of z was better.

# Japt -R, 18 bytes

îU
U+ÕÅ+UÔÅ Õ·hJUw


Test it online!

# 05AB1E, 16 bytes

×,<GgIÍ*ú«,}≠i×,


Explanation:

×          # Repeat the (implicit) input the (implicit) input amount of times as string
,         # Pop and print this string with trailing newline
<G         # Loop the (implicit) input-2 amount of times:
g        #  Get the length of the (implicit) input
IÍ      #  Push the input-2
*     #  Multiply it by the length
«   #  Append it to the (implicit) input
,  #  Pop and print it with trailing newline
}         # Close the loop
≠i       # If the (implicit) input is NOT 1:
×      #  Repeat the (implicit) input the (implicit) input amount of times as string
,     #  Pop and print this string with trailing newline


I don't think I've ever used the fact that input can be implicitly as many times in a single program as this one. xD

# Batch, 264 bytes

@echo off&setlocal enabledelayedexpansion&set o=&set m=
for /l %%i in (1,1,%1)do set o=!o!%1&if %%i gtr 2 set m=!m!%1
if %1 gtr 0 echo %o%&if %1 gtr 2 (for /l %%i in (0,1,9)do set m=!m:%%i= !
set/an=%1-2
for /l %%i in (1,1,!n!)do echo %1!m!%1)
if %1 gtr 1 echo %o%


Only works for numbers up to 2029 because of the length limitations of echo.