use strict;
use warnings;
use Data::Dumper;

my $x = 4;
my $y = 5;
my $distance_mat;
####################
for(my $i=1; $i<=$x; ++$i){
        for(my $j=0; $j<$y; ++$j){
                for(my $k=0; $k<$y; ++$k){                       
                        $distance_mat -> [$i][$j][$k] = rand 1;
                }   
        }   
}
##############Start and end nodes have zero cost
for(my $i=0; $i<scalar(@{$distance_mat->[1]}); ++$i){
        $distance_mat -> [0][0][$i] = 0;
}
for(my $i=0; $i<scalar(@{$distance_mat->[-1]}); ++$i){
        $distance_mat -> [-1][0][$i] = 0;
}

print Dumper $distance_mat;