#!/usr/bin/perl
use warnings;
use math_module;
### TO PRODUCE THE INVERSE OF A SQUARE MATRIX in PERL:
# In a square matrix the number of rows and columns are equal.
# Here we intend to get the inverse of a 4x4 square matrix.
######################################################
print"\n Here we intend to get the inverse of a 4x4 square matrix.\n";
print"\n Enter the Number of Rows i.e 4: ";
$n= <STDIN>; chomp$n;
$N=$n;              
# Input the matrix below:
$m2[0]=[3,2,1,1]; 
$m2[1]=[1,0,2,2];
$m2[2]=[4,1,3,3];
$m2[3]=[1,2,3,4];
### Data Ends Here ###########################
@inv=math_module::get_inverse($N,@m2);
##############################################
# Checking if the inverse matrix is correct:   
##############################################
for ($i=0; $i<$N; $i++)
{                         
  for ($j=0; $j<$N; $j++)
  {
     $t=0;
     for($k=0; $k<$N; $k++)
     {
        $t=$t+ $m2[$i][$k]*$inv[$k][$j];  
     }   
  } 
}
################################################# 
print "\n\n The Inverse Matrix is:\n\n";
## Use of for LOOP:  
for ($i=0; $i<$N; $i++)
{                   
  for ($j=0; $j<$N; $j++)
  {
      print $inv[$i][$j];
      print "  ";
  }
  print "\n\n";
}  
exit;