Finit le jour 3

main
Clement Desmidt 10 months ago
parent 0dc0c90964
commit 75f245787b
  1. 16
      day_3/part_1.php
  2. 52
      day_3/part_2.php

@ -0,0 +1,16 @@
<?php
$lines = array_map('str_split', explode("\n", file_get_contents('input.txt')));
$lines = array_map('array_reverse', array_map(null, ...$lines)); // matrix rotation
$gamma = '';
$epsilon = '';
foreach ($lines as $line) {
$counts = array_count_values($line);
$max = array_search(max($counts), $counts);
$gamma .= $max;
$epsilon .= $max === 1 ? 0 : 1;
}
echo bindec($gamma) * bindec($epsilon);

@ -0,0 +1,52 @@
<?php
$lines = array_map('str_split', explode("\n", file_get_contents('input.txt')));
$oxygen_lines = $lines;
for ($i = 0, $l = count($oxygen_lines[0]); $i < $l; $i++) {
if (count($oxygen_lines) <= 1) {
break;
}
$rotated_lines = array_map('array_reverse', array_map(null, ...$oxygen_lines)); // matrix rotation
$max = determine_max_number_at_line($rotated_lines, $i);
$oxygen_lines = array_filter($oxygen_lines, static function ($line) use ($max, $i) {
return $line[$i] == $max;
});
}
$co2_lines = $lines;
for ($i = 0, $l = count($co2_lines[0]); $i < $l; $i++) {
if (count($co2_lines) <= 1) {
break;
}
$rotated_lines = array_map('array_reverse', array_map(null, ...$co2_lines)); // matrix rotation
$min = determine_min_number_at_line($rotated_lines, $i);
$co2_lines = array_filter($co2_lines, static function ($line) use ($min, $i) {
return $line[$i] == $min;
});
}
$oxygen = implode(current($oxygen_lines));
$co2 = implode(current($co2_lines));
echo bindec($oxygen) * bindec($co2);
function determine_max_number_at_line($rotated_lines, $line_number): bool|int|string
{
$line = $rotated_lines[$line_number];
$counts = array_count_values($line);
if ($counts[0] === $counts[1]) {
return 1;
}
return array_search(max($counts), $counts);
}
function determine_min_number_at_line($rotated_lines, $line_number): bool|int|string
{
$line = $rotated_lines[$line_number];
$counts = array_count_values($line);
if ($counts[0] === $counts[1]) {
return 0;
}
return array_search(min($counts), $counts);
}
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