7. Reverse Integer

Difficulty: Medium 

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

Python Solution:

class Solution:
    def reverse(self, x: int) -> int: 
        x=str(x)
        x=x[::-1]
        if x[-1]=='-':
            if (-1)*int(x[:-1])<=2**31-1 and (-1)*int(x[:-1])>=-2**31:
                return (-1)*int(x[:-1])
            else:
                return 0
        else:
            if int(x)<=2**31-1 and int(x)>=-2**31:
                return int(x)
            else:
                return 0