LeetCode——7. Reverse Integer
Description
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
Note
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.
Solution
class Solution(object):
def reverse(self, x):
"""
:type x: int
:rtype: int
"""
result = 0
symbol = 1
if x <0:
symbol = -1 #设置表示负数时的情况。
x = -x
while x != 0:
result = result * 10 + x % 10
x /= 10
return 0 if result > pow(2,31) else result * symbol #判断重新生成的数是否超出了数的界限