[Leet Code] Reverse Integer

Leet Code: https://leetcode.com/problems/reverse-integer/

Problem:

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

Example 4:

Input: x = 0
Output: 0

Constraints:

• -231 <= x <= 231 - 1

Solution:

class Solution(object):
    def reverse(self, x):
        """
        :type x: int
        :rtype: int
        """
        answer = ""
        if str(x)[0] == "-":
            answer = self.reversing(str(x)[1::])
            answer = self.correctRange(answer)
            if answer == 0:
                return 0
            new_ans = "-" + str(answer)
            return new_ans
        else:
            answer = self.reversing(str(x))
            return self.correctRange(answer)
    def reversing(self,number):
        return number[::-1]
    def correctRange(self,number):
        number = int(number)
        if abs(number) < 2**31 and number != 2**31 - 1:
            return number
        else:
            return 0