From 8f3c16911ba539432cb87c7329dedc821cab30da Mon Sep 17 00:00:00 2001
From: "Jan \"Yenya\" Kasprzak" <kas@fi.muni.cz>
Date: Thu, 15 Dec 2022 08:49:04 +0100
Subject: [PATCH] Day 15: a bit polished, but still slow (43s)

---
 2022/29.pl | 28 +++++++++++-----------------
 2022/30.pl | 50 ++++++++++++++++++++------------------------------
 2 files changed, 31 insertions(+), 47 deletions(-)

diff --git a/2022/29.pl b/2022/29.pl
index 71896f3..2b7128b 100755
--- a/2022/29.pl
+++ b/2022/29.pl
@@ -7,35 +7,29 @@ use experimental 'multidimensional';
 my $row = 2000000;
 
 my @ints;
-
 my %corr;
 
 while (<>) {
 	my ($sx, $sy, $cx, $cy) = /(-?\d+)/g;
 	my $r = abs($sx - $cx) + abs($sy - $cy);
 	my $dist = abs($sy - $row);
-	say "dist =$dist";
-	if ($dist < $r) {
-		my $l = abs($dist-$r);
-		push @ints, [ $sx - ($r - $dist), $sx + ($r - $dist) ];
-		say "$ints[-1][0] $ints[-1][1]";
-		$corr{$cx} = 1 if $cy == $row;
-	}
+	next if $dist >= $r;
+
+	push @ints, [ $sx - ($r - $dist), $sx + ($r - $dist) ];
+	$corr{$cx} = 1 if $cy == $row;
 }
 
 @ints = sort { $a->[0] <=> $b->[0] } @ints;
-my $prev = shift @ints;
-my $sum = $prev->[1] - $prev->[0] + 1;
+my $sum = $ints[0][1] - $ints[0][0] + 1;
+my $prev = (shift @ints)->[1];
 
 for my $int (@ints) {
-	if ($int->[0] > $prev->[1]) {
+	if ($int->[0] > $prev) {
 		$sum += $int->[1] - $int->[0] + 1;
-		$prev = $int;
-	} elsif ($int->[1] <= $prev->[1]) {
-		next;
-	} else {
-		$sum += $int->[1] - $prev->[1];
-		$prev = $int;
+		$prev = $int->[1];
+	} elsif ($int->[1] > $prev) {
+		$sum += $int->[1] - $prev;
+		$prev = $int->[1];
 	}
 }
 
diff --git a/2022/30.pl b/2022/30.pl
index 3dc0e5f..0c3bb5a 100755
--- a/2022/30.pl
+++ b/2022/30.pl
@@ -4,54 +4,44 @@ use v5.36;
 use strict;
 use experimental 'multidimensional';
 
-my $row = 2000000;
 my $max = 4000000;
 
-my @input = <>;
+my @input = map {
+	my ($x, $y, $cx, $cy) = /(-?\d+)/g;
+	[ $x, $y, abs($x-$cx) + abs($y-$cy) ]
+} <>;
 
 sub compute_row($row) {
 	my @ints;
-	my %corr;
 
 	for (@input) {
-		my ($sx, $sy, $cx, $cy) = /(-?\d+)/g;
-		my $r = abs($sx - $cx) + abs($sy - $cy);
+		my ($sx, $sy, $r) = @$_;
 		my $dist = abs($sy - $row);
-		# say "dist =$dist";
-		if ($dist < $r) {
-			my ($l, $r) = ($sx - ($r - $dist), $sx + ($r - $dist));
-			next if $r < 0 || $l > $max;
-			$l = 0 if $l < 0;
-			$r = $max if $r > $max;
-			push @ints, [$l, $r];
-			# say "$ints[-1][0] $ints[-1][1]";
-			$corr{$cx} = 1 if $cy == $row;
-		}
+		next if $dist > $r;
+
+		my ($left, $right) = ($sx - ($r - $dist), $sx + ($r - $dist));
+		next if $right < 0 || $left > $max;
+		$left = 0 if $left < 0;
+		$right = $max if $right > $max;
+		push @ints, [$left, $right];
 	}
 
 	@ints = sort { $a->[0] <=> $b->[0] } @ints;
-	my $prev = shift @ints;
-	if ($prev->[0]) {
-		say "at 0 $row";
-		exit 0;
-	}
-	my $sum = $prev->[1] - $prev->[0] + 1;
+	my $prev = (shift @ints)->[1];
 
 	for my $int (@ints) {
-		if ($int->[0] < $max && $int->[0] > $prev->[1]+1) {
-			say "at ", $prev->[1]+1, " $row: ", 4000000*($prev->[1]+1)+$row;
+		next if $int->[1] <= $prev;
+		if ($int->[0] > $prev+1) {
+			say "at ", $prev+1, " $row: ",
+				4000000*($prev+1)+$row;
 			exit 0;
-		} elsif ($int->[1] <= $prev->[1]) {
-			next;
-		} else {
-			$prev = $int;
 		}
-		last if $prev->[1] > $max;
+		$prev = $int->[1];
 	}
 }
 
-for (1 .. $max) {
+for (0 .. $max) {
 	compute_row($_);
-	say "row $_" if $_ % 1000 == 0;
+	say "row $_" if $_ % 10_000 == 0;
 }
 
-- 
2.43.5