#!/usr/bin/perl

# http://perlmonks.org/?node_id=1186862

use strict;
use warnings;

my @arr = (19,17,22,23,24,15,16,25..35);

my @sorted = sort {$a <=> $b} @arr;
my @missing = map { $sorted[$_ - 1] + 1 .. $sorted[$_] - 1 } 1 .. $#sorted;

print "missing numbers are @missing\n";