#!/usr/bin/perl

use strict;
use warnings;

$_ = '1:1,2:1,3:2,500:2,505:1';

my (@array, %hash);

%hash = map { my @x = split /:/; push @array, $x[0]; @x } split /,/;

use Data::Dumper;

print Dumper \@array, \%hash;