<?php

$wire_paths = explode("\n", file_get_contents('input.txt'));
$wires = [];

function mark_wire_in_grid(string $wire)
{
    $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";
        }
    }

    return $points;
}

foreach ($wire_paths as $i => $wire_path) {
    $wires[] = mark_wire_in_grid($wire_path);
}

$common_points = array_intersect($wires[0], $wires[1]);

foreach ($common_points as $common_point) {
    [$x,$y] = array_map('intval', explode(',', $common_point));
    echo sprintf('Distance entre %s et %s : %s%s', $x, $y, $x + $y, "\n");
}