http://www.perlmonks.org?node_id=407183


in reply to Re: pathsearch/backtracking in Perl - how to solve a problem apparently requiring it? (comparison of Perl with Standard ML)
in thread pathsearch/backtracking in Perl - how to solve a problem apparently requiring it? (comparison of Perl with Standard ML)

Hmmm, a few fixes so you can have 0 counts for some of the coins.

use strict; my $change = 16; my @coins = sort { $b <=> $a } qw(2 5); my $q='1'x$change; my $solution = join "", map { qr[((?:.{$_})*)] } @coins; $q =~ /^$solution$/ or die "Error in regex construction"; { # This should maybe be done via @-, but I'm lazy: no strict; print(length(${$_})/$coins[$_-1], '*', $coins[$_-1]) for (1..@coins) +; }; __END__