Day 13

[aoc2020.git] / 25.pl

diff --git a/25.pl b/25.pl
new file mode 100755 (executable)
index 0000000..60b72ca
--- /dev/null
+++ b/25.pl
@@ -0,0 +1,19 @@
+#!/usr/bin/perl -w
+
+use strict;
+
+my $timestamp = <>;
+my @buses = grep { /\d+/ } split /,/, <>;
+
+my ($min_del, $min_bus);
+for my $bus (@buses) {
+       my $delay = $bus*(1+int(($timestamp-1)/$bus))-$timestamp;
+       print "Bus $bus delay $delay\n";
+       if (!defined $min_del || $min_del > $delay) {
+               $min_bus = $bus;
+               $min_del = $delay;
+       }
+}
+
+print "$min_bus * $min_del = ", $min_bus * $min_del, "\n";
+