krzysiej/advent_of_code_2021
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

5th day 2nd part

Browse Source
This commit is contained in:
kplaczek
2021-12-05 10:49:48 +01:00
parent 613487e420
commit 97e3d4b24b
2 changed files with 37 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

35
05/part2.php Normal file
View File

@@ -0,0 +1,35 @@
<?php
echo '<pre>';
$input = file('input', FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
$input = array_map(fn($line) => explode(',', str_replace(' -> ', ',', $line)), $input);
$map = array_fill(0, 1000, array_fill(0, 1000, 0));
foreach ($input as $coordinates) {
if ($coordinates[0] === $coordinates[2]) {
$start = min([$coordinates[1], $coordinates[3]]);
$end = max([$coordinates[1], $coordinates[3]]);
for ($i = $start; $i <= $end; $i++) {
$map[$coordinates[0]][$i]++;
}
}
if ($coordinates[1] === $coordinates[3]) {
$start = min([$coordinates[0], $coordinates[2]]);
$end = max([$coordinates[0], $coordinates[2]]);
for ($i = $start; $i <= $end; $i++) {
$map[$i][$coordinates[1]]++;
}
}
if ($coordinates[0] !== $coordinates[2] && $coordinates[1] !== $coordinates[3]) {
$startx = $start = min([$coordinates[0], $coordinates[2]]);
$endx = max([$coordinates[0], $coordinates[2]]);
$starty = $startx === $coordinates[0] ? $coordinates[1] : $coordinates[3];
$endy = $startx === $coordinates[2] ? $coordinates[1] : $coordinates[3];
$slope = $starty > $endy ? -1 : 1;
for ($i = $startx, $step = 0; $i <= $endx; $i++, $step++) {
$map[$i][$starty + ($step * $slope)]++;
}
}
}
echo count(array_filter(call_user_func_array('array_merge', $map), fn($el) => $el > 1)); //22213