From: Jan "Yenya" Kasprzak <kas@fi.muni.cz>
Date: Thu, 19 Dec 2024 07:29:03 +0000 (+0100)
Subject: Day 17: slow and ineffective part 2
X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?a=commitdiff_plain;h=ca91ea5f8598fab02b7d8e797f04b548de518810;p=aoc.git

Day 17: slow and ineffective part 2
---

diff --git a/2024/33.pl b/2024/33.pl
new file mode 100755
index 0000000..81c215c
--- /dev/null
+++ b/2024/33.pl
@@ -0,0 +1,46 @@
+#!/usr/bin/perl -w
+
+use v5.40;
+
+my @reg;
+push @reg, <> =~ /\d+/g for 1 .. 3;
++<>;
+my @prog = <> =~ /\d+/g;
+
+my $pc = 0;
+my @out;
+while ($pc < @prog) {
+	my ($opc, $arg) = @prog[$pc, $pc+1];
+	last if !defined $pc;
+	my $combo;
+	if ($arg < 4) {
+		$combo = $arg;
+	} elsif ($arg < 7) {
+		$combo = $reg[$arg-4];
+	} else {
+		die "Combo arg $arg";
+	}
+	if ($opc == 0) {
+		$reg[0] = int ($reg[0] / (1 << $combo));
+	} elsif ($opc == 1) {
+		$reg[1] ^= $arg;
+	} elsif ($opc == 2) {
+		$reg[1] = $combo & 0x7;
+	} elsif ($opc == 3) {
+		if ($reg[0]) {
+			$pc = $arg - 2;
+		}
+	} elsif ($opc == 4) {
+		$reg[1] ^= $reg[2];
+	} elsif ($opc == 5) {
+		push @out, $combo & 0x7;
+	} elsif ($opc == 6) {
+		$reg[1] = int ($reg[0] / (1 << $combo));
+	} elsif ($opc == 7) {
+		$reg[2] = int ($reg[0] / (1 << $combo));
+	} else {
+		die "Unknown opcode $opc";
+	}
+	$pc += 2;
+}
+say join(',', @out);
diff --git a/2024/34.pl b/2024/34.pl
new file mode 100755
index 0000000..976784f
--- /dev/null
+++ b/2024/34.pl
@@ -0,0 +1,77 @@
+#!/usr/bin/perl -w
+
+use v5.40;
+use List::Util qw(min);
+
+my @reg;
+push @reg, <> =~ /\d+/g for 1 .. 3;
++<>;
+my @prog = <> =~ /\d+/g;
+
+sub run($m) {
+	my @out;
+	while ($m->{pc} < @{ $m->{prog} }) {
+		my ($opc, $arg) = @{ $m->{prog} }[$m->{pc}, $m->{pc}+1];
+		last if !defined $arg;
+		my $combo;
+		if ($arg < 4) {
+			$combo = $arg;
+		} elsif ($arg < 7) {
+			$combo = $m->{reg}->[$arg-4];
+		} else {
+			die "Combo arg $arg";
+		}
+		if ($opc == 0) {
+			$m->{reg}->[0] = $m->{reg}->[0] >> $combo;
+		} elsif ($opc == 1) {
+			$m->{reg}->[1] ^= $arg;
+		} elsif ($opc == 2) {
+			$m->{reg}->[1] = $combo & 0x7;
+		} elsif ($opc == 3) {
+			if ($m->{reg}->[0]) {
+				$m->{pc} = $arg - 2;
+			}
+		} elsif ($opc == 4) {
+			$m->{reg}->[1] ^= $m->{reg}->[2];
+		} elsif ($opc == 5) {
+			my $val = $combo & 0x7;
+			my $ex = shift @{ $m->{ex} };
+			return undef if $val != $ex;
+			return 1 if !@{ $m->{ex} };
+		} elsif ($opc == 6) {
+			$m->{reg}->[1] = $m->{reg}->[0] >> $combo;
+		} elsif ($opc == 7) {
+			$m->{reg}->[2] = $m->{reg}->[0] >> $combo;
+		} else {
+			die "Unknown opcode $opc";
+		}
+
+		$m->{pc} += 2;
+	}
+	return @{ $m->{ex} } ? 0 : 1;
+}
+
+my @valid = (0);
+for my $l (0 .. $#prog) {
+	say "$l: ", join(',', @prog[0 .. $l]);
+	my @nv;
+	my %seen = ();
+	for my $i (0 .. 1023) {
+		my $ii = $i << (3*$l);
+		for my $v (@valid) {
+			my $val = $v;
+			$val ^= $ii;
+			next if $seen{$val}++;
+			my $rv = run({
+				reg  => [ $val, 0, 0 ],
+				prog => \@prog,
+				pc   => 0,
+				ex   => [ @prog[0 .. $l] ],
+			});
+			next if !$rv;
+			push @nv, $val;
+		}
+	}
+	@valid = @nv;
+}
+say min @valid;