int divide(int a, int b){
    if (a == INT_MIN && b == -1) {
            return INT_MAX;
        }

        /*
            判断是否同号，同号则 结果为正数
         */
        bool flag = false;
        if ((a<0 && b<0) || (a>0 && b>0)) {
            flag = true;
        }

        long dividend = labs(a);
        long divisor = labs(b);
        if (dividend < divisor) {
            return 0;
        }
        /*
            计算 结果的绝对值
         */
        long result = 0;
        long shift = 31;
        while (dividend >= divisor) {
            while (dividend < divisor << shift) {
                shift--;
            }
            dividend -= divisor << shift;
            result += (uint32_t)1 << shift;
        }

        return flag ? result : -result;
}