use strict; use warnings; comb('', 4, 1..4,6..9); sub comb { my ($str, $depth, @items) = @_; if (!$depth--) { interpret($str); return; } comb("$str $items[$_]", $depth, @items[($_+1)..$#items]) for (0..$#items) } sub interpret { my @cards = split / /, "5$_[0]"; @cards = sort {$b <=> $a} @cards; my $flag = 1; for (0..3) { $flag = 0 if $cards[$_+1] != ($cards[$_]-1); } return if $flag; for (perm(@cards)) { return if sum(split //) == 15; } print join " ", @cards; } BEGIN { my @c_out; sub perm { @c_out = (); permute('', $_, @_) for (0..$#_); return @c_out; } sub permute { my ($str, $depth, @chars) = @_; if (!$depth--) { push @c_out, $str.$_ for @chars; } else { permute($str.$chars[$_], $depth, @chars[($_+1)..($#chars)]) for (0..$#chars); } } } sub sum { my $n; $n += $_ for @_; return $n; }