7. Reverse Integer

Given a 32-bit signed integer, reverse digits of an integer.

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.

 1 class Solution {
 2 public:
 3     int reverse(int x) {
 4         int64_t res=0; //如果用int会溢出, runtime error
 5         while(x!=0)
 6         {
 7             int tmp=res*10+x%10;
 8             if((tmp-x%10)/10!=res)
 9                 return 0;
10             x/=10;
11             res=tmp;
12         }
13         return res;
14     }
15 };

7. Reverse Integer

原文：https://www.cnblogs.com/lychnis/p/11667090.html