From: Jan "Yenya" Kasprzak <kas@fi.muni.cz>
Date: Wed, 10 Dec 2025 18:09:53 +0000 (+0100)
Subject: Day 10: simplex method
X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?a=commitdiff_plain;h=55ee1c1053a65cb2d991ba4596d332bab10a84df;p=aoc.git

Day 10: simplex method
---

diff --git a/2025/19.pl b/2025/19.pl
new file mode 100755
index 0000000..8c28c03
--- /dev/null
+++ b/2025/19.pl
@@ -0,0 +1,32 @@
+#!/usr/bin/perl -w
+
+use v5.42;
+
+my $sum;
+
+while (<>) {
+	/(?<=\[).*?(?=\])/;
+	my $state = $&;
+	my @btns = map { [ /\d+/g ] } /\(.*?\)/g;
+
+	my @q = [ $state, 0, -1 ];
+	while (my $f = shift @q) {
+		my ($state, $n, $b, @rest) = @$f;
+		if ($state !~ /#/) {
+			$sum += $n;
+			last;
+		}
+		$n++;
+		for my $btn ($b+1 .. $#btns) {
+			my $b = $btns[$btn];
+			my $nstate = $state;
+			for my $i (@$b) {
+				substr($nstate, $i, 1) =~ y/#./.#/;
+			}
+			push @q, [ $nstate, $n, $btn, @rest, $btn ];
+		}
+	}
+	
+}
+	
+say $sum;
diff --git a/2025/20.pl b/2025/20.pl
new file mode 100755
index 0000000..11fb8be
--- /dev/null
+++ b/2025/20.pl
@@ -0,0 +1,38 @@
+#!/usr/bin/perl -w
+
+# Run as
+# ./20.pl input.txt  > x.py && python3 x.py  | perl -lnE '$sum += $_ }{ say $sum'
+
+use v5.42;
+use List::Util qw(max);
+
+say "import z3";
+say "sum = 0";
+
+while (<>) {
+	/(?<=\{).*?(?=\})/;
+	my @state = split /,/, $&;
+	my @btns = map { [ /\d+/g ] } /\(.*?\)/g;
+
+	my $m;
+	my $max = max @state;
+	push @$m, [ (0) x @btns, $_ ] for @state;
+	for my ($i, $btn) (indexed @btns) {
+		$m->[$_][$i] = 1 for @$btn;
+	}
+	say "s = z3.Optimize()";
+	say join(', ', map { "x$_" } 0 .. $#btns), " = z3.Ints('",
+		join(' ', map { "x$_" } 0 .. $#btns), "')";
+	say "s.add(x$_ >= 0)" for 0 .. $#btns;
+	for my $row (@$m) {
+		say "s.add(", join(' + ', map { "x$_" } grep { $row->[$_] } 0 .. $#$row - 1), ' == ', $row->[-1], ")"
+	}
+	say "s.minimize(", join(' + ', map { "x$_" } 0 .. $#btns), ")";
+	say "s.check()";
+	say "m = s.model()";
+	say "val = m.eval(", join(' + ', map { "x$_" } 0 .. $#btns), ")";
+	say "print(val)";
+	say "sum = sum + val";
+	say "";
+}
+say "print(sum)"