package part2; use 5.20.0; use warnings; use List::AllUtils qw/ /; require './part1.pm'; use experimental qw/ signatures postderef /; sub solution(@seeds) { my $last = shift @seeds; my $turn = 1; my %said; for(@seeds) { $said{$last} ||= []; push $said{$last}->@*, $turn++; $last = $_; } until( $turn == 30000000 ) { if( !$said{$last} ) { $said{$last} = [$turn]; $last = 0 } else { push $said{$last}->@*, $turn; if( $said{$last}->@* > 2 ) { shift $said{$last}->@*; } $last = $said{$last}[-1] - $said{$last}[-2]; } $turn++; } return $last; } 1;