leetcode: explore-strings-33 反转字符串

Given a 32-bit signed integer, reverse digits of an integer.

Example 1:

Input: 123
Output: 321
Example 2:

Input: -123
Output: -321
Example 3:

Input: 120
Output: 21
Note:
Assume we are dealing with an environment which could only store integers within the 32-bit signed integer range: [−2^31,  2^31 − 1]. For the purpose of this problem, assume that your function returns 0 when the reversed integer overflows.

class Solution(object):
    def reverse(self, x):
        """
        :type x: int
        :rtype: int
        """
        flag = True if x < 0 else False
        s = str(abs(x))
        s = int(s[::-1]) if not flag else -int(s[::-1])
        # if s > (pow(2, 31) - 1) or s < (pow(-2, 31) - 1):
        #     return 0

        v_max = 0xffffffff/2
        if s > (v_max - 1) or s < (v_max*(-1)):
            return 0
        return s


if __name__ == "__main__":
    s = Solution()
    print(s.reverse(123))
    print(s.reverse(-123))
    print(s.reverse(-120))
    print(s.reverse(1534236469))