Advent of code 2019/13

Ajax Direct

class Game extends Intcode
{
    /**
     * Output a value
     *
     * @param int $value
     * @return void
     */
    public function sendOutput($value)
    {
        $last = $this->output->last();

        // Add to last group of 3
        if ($last && count($last) < 3) {
            $this->output[$this->output->count() - 1][] = $value;
            return;
        }

        // Start new group
        $this->output[] = [$value];
    }

    /**
     * Get an input
     *
     * @return int
     */
    public function getInput()
    {
        // Get the ball & paddle positions
        foreach ($this->output as $pos) {
            if ($pos[2] == 3) $paddle = $pos;
            if ($pos[2] == 4) $ball = $pos;
        }
        // Move the paddle to be under the ball (-1, 0, 1)
        return $ball[0] <=> $paddle[0];
    }
}

// ==================================================
// > PART 1
// ==================================================
$game_1 = (new Game($input)); $game_1->run();
$solution_1 = $game_1->output->column(2)->keep([2])->count();

// ==================================================
// > PART 2
// ==================================================
$memory = $input->numbers; $memory[0] = 2;
$game_2 = (new Game($memory)); $game_2->run();

// Find last score at position -1, 0
foreach ($game_2->output->reverse() as $pos) {
    if ($pos[0] == -1 && $pos[1] == 0) {
        $solution_2 = $pos[2];
        break;
    }
}