use strict;
use warnings;
use List::Util qw/sum/;

# finds one solution
sub findsum {
		my ($target, @array) = @_;
		while( @array ) {
				my $cand = shift @array;
				return () if $cand > $target;
				return ( $cand ) if $cand==$target;
				my @sol = findsum( $target-$cand, @array );
				return ($cand, @sol) if @sol;
		}
		return ();
}

my @array = qw(1 3 5 7);
my $total = sum(@array);

die "Odd total $total cannot be split!\n" if $total % 2;

my @sol = findsum( $total/2, sort @array );
if( @sol ) {
		print "Solution: ",join( ",", @sol), "\n";
} else {
		print "No solution.";
}