ACM_Someone like you

int reverse(int x) {
    long sumLong = 0;
    int sum = 0;
    int num =  0;
    while (x!= 0) {    //支持正負數
        num = x % 10;  //末尾數字
        sum = sum * 10;//進位
        sum += num;
        x = x / 10;
        //校驗精度
        sumLong = sumLong * 10;
        sumLong += num;
        if (sumLong != sum) {
            sum = 0;
            break;
        }
    }
    return sum;
}