#!/usr/bin/perl # http://perlmonks.org/?node_id=1213986 use strict; # solver use warnings; $_ = <@*; local $_ = $prev[-1]; $seen{$_}++ and next; if( /^.*R/ ) { my $moves = @prev - 1; my $count = 0; print "WINNER in $moves moves\n\n", map "\n " . $count++ . "\n$_", @prev; exit; } while( / ((\w)\2+)/g ) { push @queue, [ @prev, "$`$1 $'" ]; } while( /((\w)\2+) /g ) { push @queue, [ @prev, "$` $1$'" ]; } $_ = transpose($_); while( / ((\w)\2+)/g ) { push @queue, [ @prev, transpose("$`$1 $'") ]; } while( /((\w)\2+) /g ) { push @queue, [ @prev, transpose("$` $1$'") ]; } } print "Unsolvable\n"; sub transpose { local $_ = shift; my $answer = ''; $answer .= "\n" while s/^./ $answer .= $&; ''/gem; return $answer; }