7. Reverse Integer

Medium (Trung bình) Python 🔗 Xem trên LeetCode

📋 Đề Bài

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

💻 Lời Giải

Python 0007-reverse-integer.py 
class Solution:
    def reverse(self, x: int) -> int:
        front = [1, -1][x < 0]
        
        num = front * int(str(abs(x))[::-1])
        
        return num if -2**31 <= num <= 2**31 - 1 else 0