Reverse Integer

题目：

Reverse digits of an integer. For example: x = 123, return 321

解答：

public int reverse(int x) {
    int ret = 0;

    while(x != 0) {
        // handle overflow/underflow
        if(Math.abs(ret) > 214748364) {
            return 0;
        }

        ret = ret * 10 + x % 10;
        x = x / 10;
    }

    return ret;
}