Quiz 79: Print a square matrix in anti-clockwise direction

Problem:

Given a positive integer(n), print square matrix(n x n) in anticlockwise direction.
Check sample input/output for better understanding

Input Format: 

N=a positive integer

Output Format: 

square matrix in anti-clockwise direction

Constraints: 
None

Sample Input

4

Sample Output:

1 12 11 10
2 13 16 9
3 14 15 8
4 5 6 7

Explanations:

in a matrix, 4 x 4, starting printing numbers from 1 in anticlockwise direction ie down,right,up,left.

---

Solution:

use strict;
use warnings;

my $n=<STDIN>;
my $m=$n;
my @arr=();
my $ans=1;
my $row=0;
my $col=$n-1;
my $i=0;
my $j=0;
while($n>=1)
{
for($i=$row;$i<=$col;$i++)
{
$arr[$i][$row]=$ans;
$ans++;
}
for($i=$row+1;$i<=$col;$i++)
{
$arr[$col][$i]=$ans;
$ans++;
}
for($i=$col-1;$i>=$row;$i--)
{
$arr[$i][$col]=$ans;
$ans++;
}
for($i=$col-1;$i>=$row+1;$i--)
{
$arr[$row][$i]=$ans;
$ans++;
}
$n=$n-2;
$row=$row+1;
$col=$col-1;
}
for($i=0;$i<$m;$i++)
{
for($j=0;$j<$m;$j++)
{
print "$arr[$i][$j] ";
}
print "\n";
}

---

Tips:

On completing 1 full anticlockwise cycle, the dimension of matrix will change by 2, so i used $n=$n-2