from lib import Grid2D, add2


def part_1(data):
    steps = 10_000

    g = Grid2D(data)
    # g.print()
    dirs = [g.N, g.E, g.S, g.W]

    pos = (g.n_rows // 2, g.n_cols // 2)
    dir = g.N

    inf = set(g.find("#"))

    burst_inf = 0
    for _ in range(steps):
        if pos in inf:
            # turn right
            dir = dirs[(dirs.index(dir) + 1) % len(dirs)]
            inf.remove(pos)
        else:
            # turn left
            dir = dirs[(dirs.index(dir) - 1) % len(dirs)]
            inf.add(pos)
            burst_inf += 1
        pos = add2(pos, dir)
    print(burst_inf)


def part_2(data):
    steps = 10000000

    g = Grid2D(data)
    dirs = [g.N, g.E, g.S, g.W]

    pos = (g.n_rows // 2, g.n_cols // 2)
    dir = g.N

    weak = set()
    inf = set(g.find("#"))
    flagged = set()

    burst_inf = 0
    for _ in range(steps):
        if pos in weak:
            weak.remove(pos)
            inf.add(pos)
            burst_inf += 1
        elif pos in inf:
            dir = dirs[(dirs.index(dir) + 1) % len(dirs)]
            inf.remove(pos)
            flagged.add(pos)
        elif pos in flagged:
            dir = dirs[(dirs.index(dir) + 2) % len(dirs)]
            flagged.remove(pos)
        else:
            dir = dirs[(dirs.index(dir) - 1) % len(dirs)]
            weak.add(pos)
        pos = add2(pos, dir)
    print(burst_inf)


def main():
    data = open(0).read()
    part_1(data)
    part_2(data)


if __name__ == "__main__":
    main()