29. Divide Two Integers

class Solution {
public:
    const int MAX_INT = 2147483647;
    typedef long long ll;
    int divide(int dividend, int divisor) {
        ll a = abs(ll(dividend));    //pay attention to negative num &&&& not abs(dividend);
        ll b = abs(ll(divisor));
        cout<<a<<' '<<b<<endl;
        ll res = 0;
        while (a >= b) {
            ll tmp = b;
            ll cnt = 1;
            while ((tmp << 1) <= a) {
                tmp <<= 1;
                cnt <<= 1;
            }
            res += cnt;
            a -= tmp;
        }

        if ((dividend > 0 && divisor < 0) || (dividend < 0 && divisor > 0)) res = -res;
        if (res > MAX_INT) res = MAX_INT;
        return res;
    }
};