Add day 3 part 2

This commit is contained in:
Clement Desmidt 2019-12-06 16:35:31 +01:00
parent 207d834b60
commit ecf949607b
1 changed files with 41 additions and 0 deletions

41
day_3/part_2.php Normal file
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<?php
$wire_paths = explode("\n", file_get_contents('input.txt'));
$wires = [];
function mark_wire_in_grid(string $wire)
{
$steps = 0;
$mapping = [
'U' => [0,1],
'D' => [0,-1],
'L' => [-1,0],
'R' => [1,0],
];
$points = [];
$path = explode(',', $wire);
$current_point_x = 0;
$current_point_y = 0;
foreach ($path as $dot) {
$direction = $dot[0];
$number = (int) substr($dot, 1);
for ($t = 0; $t < $number; $t++) {
$current_point_x += $mapping[$direction][0];
$current_point_y += $mapping[$direction][1];
$points["$current_point_x,$current_point_y"] = ++$steps;
}
}
return $points;
}
foreach ($wire_paths as $i => $wire_path) {
$wires[] = mark_wire_in_grid($wire_path);
}
$common_points = array_intersect_key($wires[0], $wires[1]);
$total_steps = [];
foreach ($common_points as $coordinates => $steps) {
$total_steps[$coordinates] = $wires[0][$coordinates] + $wires[1][$coordinates];
}
echo sprintf('Le plus court pas : %s', min($total_steps));