Reverse Integer（Leetcode）

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.

反转整数，如果结果不在整数范围内就返回0。

思路：不断使用取余和取整。

class Solution {
public:
	int reverse(int x) {
		long tmp = 0;
		
		while (x!=0) {
			tmp = tmp * 10 + x % 10;
			x = x / 10;
		}
		if (tmp<INT_MIN || tmp>INT_MAX) {
			return 0;
		}
		return tmp;
	}
};