Leetcode 7 - Reverse Integer

Reverse digits of an integer.

Example1: x = 123, return 321
Example2: x = -123, return -321

Have you thought about this?
Here are some good questions to ask before coding. Bonus points for you if you have already thought through this!

If the integer’s last digit is 0, what should the output be? ie, cases such as 10, 100.

Did you notice that the reversed integer might overflow? Assume the input is a 32-bit integer, then the reverse of 1000000003 overflows. How should you handle such cases?

For the purpose of this problem, assume that your function returns 0 when the reversed integer overflows.

细节实现题，主要注意两点：
1 - 符号问题。首先要判断x的正负。
2 - 溢出问题。需要在每次循环开始前判断此次循环是否会导致溢出。若溢出则返回0。

class Solution {public:    int reverse(int x) {        int result = 0;        int sign = 1;        if(x<0){            sign = -1;            x *= -1;        }        while(x){            //溢出条件            if(result>INT_MAX/10||INT_MAX-result*10<x%10) return 0;            result *= 10;            result += x%10;            x /= 10;        }        return result*sign;    }};