题解 | #牛牛的特殊数字#

#
# 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
#
#
# @param num int整型
# @return bool布尔型
#
class Solution:
    def isSpecialNumber(self, num: int) -> bool:
        # write code here
        num = list(map(int, str(num)))
        self.bit_sum = []
        self.key = False

        def get_bit_sum(start):
            if self.key:
                return
            if start == len(num):
                self.key = judge(self.bit_sum)
                return
            self.bit_sum.append(num[start])
            get_bit_sum(start + 1)
            self.bit_sum.pop()
            if not self.bit_sum:
                return
            if len(self.bit_sum) > 1 or self.bit_sum[0] > 1:
                self.bit_sum[-1] -= 1
                self.bit_sum.append(10 + num[start])
                get_bit_sum(start + 1)
                self.bit_sum.pop()
                self.bit_sum[-1] += 1
            elif self.bit_sum[0] == 1:
                self.bit_sum[0] = 10 + num[start]
                get_bit_sum(start + 1)
                self.bit_sum[0] = 1
            return

        def judge(num: list):
            if num == 0:
                return True
            if num == num[::-1]:
                if len(num) % 2 == 0:
                    return True
                elif num[len(num) // 2] % 2 == 0:
                    return True
            return False

        get_bit_sum(0)
        return self.key