Advent of code 2018/10
Ajax Direct

Answer ⏱ 2680ms

Part 1 : #    #  ######  #    #  #####   #       #####   #    #  #    # ##   #  #       #    #  #    #  #       #    #  #    #  #   #  ##   #  #        #  #   #    #  #       #    #   #  #   #  #   # #  #  #        #  #   #    #  #       #    #   #  #   # #    # #  #  #####     ##    #####   #       #####     ##    ##     #  # #  #         ##    #       #       #  #      ##    ##     #  # #  #        #  #   #       #       #   #    #  #   # #    #   ##  #        #  #   #       #       #   #    #  #   #  #   #   ##  #       #    #  #       #       #    #  #    #  #   #  #    #  ######  #    #  #       ######  #    #  #    #  #    # Part 2 : 10459 
$points = $input->lines->map(fn ($l) => $l->numbers());

function get_message($points, $time = 0) {
    $grid = new Grid();
    foreach ($points as $p) {
        $grid->set([$p[0] + $p[2] * $time, $p[1] + $p[3] * $time], "#");
    }
    return $grid;
}


// Start at an heuristic time
$time = round(abs($points[0][0] / $points[0][2]));
$width = INF;

// Find the first time where the message is the smallest
while (true) {
    $grid = get_message($points, $time);
    if ($grid->width() > $width) break;
    $width = $grid->width();
    $time++;
}

$solution_1 = (string) get_message($points, $time - 1);
$solution_2 = $time - 1;