#!/usr/bin/perl
use strict;
use warnings;
use Storable;

my $number_contaminant = 100;

my %param = (range_contx => 100,
             range_conty => 100 );

my @grid;
 
for (1 .. $number_contaminant) {  
	#random positions of the contaminants, put the random number as integrer  
	my $x = int(rand $param{range_contx});  
	my $y = int(rand $param{range_conty}); 
	redo if $grid[$x][$y]; # if already marked
	$grid[$x][$y] = 1;
}
 
store \@grid, 'grid.dat';
store \%param, 'param.dat';