2024-05-26 17:44:15 +0000 UTC

class Solution:
    def checkRecord(self, n: int) -> int:
        temp: list[list[list[int]]] = [
            [[-1 for _ in range(3)] for _ in range(2)] for _ in range(n)
        ]  # temp[cur_ind][count_a][count_l]
        MOD: int = 10**9 + 7

        def check_all_records(cur_ind, count_a, count_l) -> int:
            if cur_ind == n:
                return 1
            if temp[cur_ind][count_a][count_l] != -1:
                return temp[cur_ind][count_a][count_l]
            with_a_next: int = check_all_records(cur_ind + 1, count_a + 1, 0) if count_a == 0 else 0
            with_l_next: int = 0 if count_l == 2 else check_all_records(cur_ind + 1, count_a, count_l + 1)
            with_p_next: int = check_all_records(cur_ind + 1, count_a, 0)
            total: int = (with_a_next + with_l_next + with_p_next) % MOD

            temp[cur_ind][count_a][count_l] = total
            return total

        return check_all_records(0, 0, 0)