From 0cdd96c5f32fe639f00d6d08f68def12b160feac Mon Sep 17 00:00:00 2001 From: June McEnroe Date: Sun, 12 Dec 2021 13:22:37 -0500 Subject: Pop instead of shift BFS isn't needed. This uses less memory and time. --- 2021/day12.pl | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/2021/day12.pl b/2021/day12.pl index a47c9b0..90f3e54 100644 --- a/2021/day12.pl +++ b/2021/day12.pl @@ -11,7 +11,7 @@ while (<>) { my $paths = 0; my @queue = (['start']); while (@queue) { - my @path = @{shift @queue}; + my @path = @{pop @queue}; my %visited = map { $_ => 1 } @path; for (@{$edges{$path[0]}}) { if ($_ eq 'end') { @@ -28,7 +28,7 @@ print "$paths\n"; $paths = 0; @queue = (['start']); while (@queue) { - my @path = @{shift @queue}; + my @path = @{pop @queue}; my (%visited, $twice); for (@path) { $twice = 1 if $visited{$_}++ && /[a-z]/; -- cgit 1.4.1