class Solution {
public:
    int divide(int dividend, int divisor) {
        long long res = 0;
        long long m = abs((long long)dividend), n = abs((long long)divisor);
        if (m < n) return 0;
        long long t = n, p = 1;
        while (m > (t << 1)) {
            t <<= 1;
            p <<= 1;
        }
        res += p + divide(m - t, n);
        if ((dividend < 0) ^ (divisor < 0)) res = -res;
        return res > INT_MAX ? INT_MAX : res;
    }
};

leetcode 29 Divide Two Integers