Skip to content

7. Reverse Integer

Difficulty Topics

Description

Given a signed 32-bit integer x, return x with its digits reversed. If reversing x causes the value to go outside the signed 32-bit integer range [-231, 231 - 1], then return 0.

Assume the environment does not allow you to store 64-bit integers (signed or unsigned).

 

Example 1:

Input: x = 123
Output: 321

Example 2:

Input: x = -123
Output: -321

Example 3:

Input: x = 120
Output: 21

 

Constraints:

  • -231 <= x <= 231 - 1

Solution

reverse-integer.py
class Solution(object):
    def reverse(self, x):
        """
        :type x: int
        :rtype: int
        """
        n = cmp(x, 0) * int(str(abs(x))[::-1])
        return n if n.bit_length() < 32 else 0