以下是一个可能的解决方案: ```python import math class Solution: def countEligibleCows(self, digits, n): str_n = str(n) num_wei = len(str_n) num_digits = len(digits) counter = 0 def generate_numbers(cur_num, cur_pos): nonlocal counter if cur_pos == num_wei: if cur_num < n: counter += 1 return for digit in digits: new_num = cur_num * 10 + digit if new_num < n: generate_numbers(new_num, cur_pos + 1) generate_numbers(0, 0) return counter def main(): digits = [1, 2, 3] n = 20 solution = Solution() result = solution.countEligibleCows(digits, n) print(result) if __name__ == "__main__": main() ``` 在上述代码中,定义了一个内部函数 `generate_numbers` 用于递归生成数字,并在生成的数字小于 `n` 时增加计数器 `counter` 的值。在 `main` 函数中给出了示例的输入和输出。 [2024-10-26 14:58:21 | AI写代码神器 | 292点数解答]