fun main() {
    val lines = readInput("day14_input")
    val (sandStart, cols) = 500 to 1000
    var (ans1, ans2) = 0 to 0

    // mapping each point p to an integer k where p_x = k%cols and p_y = k/cols
    val paths: List<List<Int>> = lines.map { it.split(" -> ").map { it.split(",").map { it.toInt() }.let { it.first() + cols*it.last() } } }
    val rows = paths.flatten().max()/cols + 2
    val points = BooleanArray((rows + 1)*(cols + 1))

    paths.forEach {
        it.windowed(2).forEach {
            val (l, h) = it.sorted()
            val range = if (l%cols != h%cols) l..h else l..h step cols
            range.forEach { points[it] = true }
        }
    }

    val last = points.indices.filter { points[it] }.max()
    val bottom = (rows*cols until (rows + 1)*cols)
    bottom.forEach { points[it] = true }

    while (true) {
        var k = sandStart
        while (k < cols*rows) {
            k += when {
                !points[k + cols]     -> cols
                !points[k + cols - 1] -> cols - 1
                !points[k + cols + 1] -> cols + 1
                else                  -> { points[k] = true; break }
            }
        }
        if (k > last && ans1 == 0) ans1 = ans2
        if (points[sandStart]) break
        ans2++
    }
    println(ans1)
    println(++ans2)
}

