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.

Note

数位分离，注意要求overflow返回0

Code

class Solution {
    public int reverse(int x) {
        int result = 0;
        int tail, newresult;
        while (x != 0) {
            tail = x % 10;
            newresult = result*10 + tail;
            if ((newresult - tail) / 10 != result)
                return 0;
            result = newresult;
            x = x / 10;
        }
        return result;
    }
}