#!/usr/bin/perl -l
use strict;
use warnings;

my @arr1 = qw(john:::10 bill:::9 mary:::35 willy:::21);
my @arr2 = qw(9 35 10 21);

my $i = 0;
my %order = map { $_ => $i++ } @arr2;

print for sort { my ($c) = $a =~ /:::(\d+)$/;
                 my ($d) = $b =~ /:::(\d+)$/;
                 $order{$c} <=> $order{$d}
               } @arr1;