链接:
https://leetcode.com/problems/reverse-integer/description/
题目:
Given a 32-bit signed integer, reverse digits of an integer.
Example:
Example 1:
Input: 123
Output: 321
Example 2:
Input: -123
Output: -321
Example 3:
Input: 120
Output: 21
Notes:
Assume we are dealing with an environment which could only store integers within the 32-bit signed integer range: [−231, 231 − 1]. For the purpose of this problem, assume that your function returns 0 when the reversed integer overflows.
解析:
- 将整数符号记录下
- 由于整数无法直接进行操作,所以转化成字符串反转
解答:
class Solution(object):
def reverse(self, x):
"""
:type x: int
:rtype: int
"""
#s = cmp(x,0)
s = (x>0) - (x<0)
r = int(str(s*x)[::-1])
if r > 2**31:
return 0
return s*r