X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?a=blobdiff_plain;f=42.pl;fp=42.pl;h=05bf2ac85b7635f81f547fe8242a901a8d90da40;hb=63b534141e63cf51990d5fa2234e1d21f0bc1bbc;hp=0000000000000000000000000000000000000000;hpb=a5a6272d28f8ecd0c24250cbf75f195ed5385e72;p=aoc2020.git

diff --git a/42.pl b/42.pl
new file mode 100755
index 0000000..05bf2ac
--- /dev/null
+++ b/42.pl
@@ -0,0 +1,42 @@
+#!/usr/bin/perl -w
+
+use strict;
+
+my %allergens;
+my %is_al;
+
+while (<>) {
+	chomp;
+	my ($ingr, $al) = /\A([^\(]+) \(contains (.*)\)\z/;
+	my %ingr = map { $_ => 1 } split /\s+/, $ingr;
+	my @al = split /, /, $al;
+	for my $al (@al) {
+		if (defined $allergens{$al}) {
+			for my $in1 (keys %{ $allergens{$al} }) {
+				if (! $ingr{$in1}) {
+					delete $allergens{$al}->{$in1};
+				}
+			}
+		} else {
+			$allergens{$al} = { %ingr };
+		}
+	}
+}
+
+AGAIN:
+for my $al (keys %allergens) {
+	if (keys %{ $allergens{$al} } == 1) {
+		my $in1;
+		for my $in (keys %{ $allergens{$al} }) {
+			$is_al{$in} = $al;
+			$in1 = $in;
+		}
+		delete $allergens{$al};
+		for my $al1 (keys %allergens) {
+			delete $allergens{$al1}->{$in1};
+		}
+		goto AGAIN;
+	}
+}
+
+print join(',', sort { $is_al{$a} cmp $is_al{$b} } keys %is_al), "\n";