Reverse Integer

题目：
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.

注意：题中已经给出，超范围时返回0.int型数据是4字节，32位，INT_MAX = 2^31-1，INT_MIN= -2^31.如果想表示的整数超过了该限值，可以使用长整型long long 占8字节64位。

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