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Add day 10 part 1

master
Clement Desmidt 2 years ago
parent
commit
51860c5116
  1. 44
      day_10/functions.php
  2. 54
      day_10/part_1.php

44
day_10/functions.php

@ -0,0 +1,44 @@
<?php
/**
* @param array $array
* @return array|bool
*/
function array_flatten(array $array) {
return iterator_to_array(array_flatten_iterator($array), false);
}
/**
* @param array $array
* @return Generator
*/
function array_flatten_iterator(array $array) {
foreach ($array as $value) {
if (is_array($value)) {
yield from array_flatten_iterator($value);
} else {
yield $value;
}
}
}
/**
* @param int $x1
* @param int $y1
* @param int $x2
* @param int $y2
*
* @return array
*/
function getPointsBetween(int $x1, int $y1, int $x2, int $y2)
{
$dx = $x2-$x1;
$dy = $y2-$y1;
$max = max(abs($dx), abs($dy));
for($t = 0; $t<=$max; $t++) {
$points[] = sprintf('%s,%s', $x1+($t*$dx)/$max, $y1+($t*$dy)/$max);
}
return $points;
}

54
day_10/part_1.php

@ -0,0 +1,54 @@
<?php
include 'functions.php';
$rows = explode("\n", file_get_contents('input.txt'));
// Make the list of asteroids coordinates
$asteroids = array_flatten(
array_filter(
array_map(static function($row, $i) {
return array_filter(array_map(static function($col, $j) use ($i) {
if ($col === '#') {
return sprintf('%s,%s', $i, $j);
}
return null;
}, str_split($row), range(0, strlen($row))));
}, $rows, range(0, count($rows)))
)
);
$asteroid_count = [];
foreach ($asteroids as $asteroid_base) {
$count = 0;
foreach ($asteroids as $asteroid_target) {
if ($asteroid_base === $asteroid_target) {
continue;
}
$points_base = explode(',', $asteroid_base);
$points_target = explode(',', $asteroid_target);
$points = getPointsBetween($points_base[0], $points_base[1], $points_target[0], $points_target[1]);
$add_point = true;
foreach ($points as $point) {
if ($point === $asteroid_base || $point === $asteroid_target) {
continue;
}
if (in_array($point, $asteroids)) {
$add_point = false;
break;
}
}
if ($add_point) {
$count++;
}
}
$asteroid_count[$asteroid_base] = $count;
}
arsort($asteroid_count);
var_dump($asteroid_count);
echo current($asteroid_count);
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