29. Divide Two Integers

class Solution {
public:
    int divide(int dividend, int divisor) {
        if(dividend ==0)
        {
            return 0;
        }
        if(divisor == 1)
        {
            return dividend;
        }
        if(divisor == -1)
        {
            if(dividend == INT_MIN)
            {
                return INT_MAX;
            }
            return -dividend;
        }

        int flag = 1;
        if((dividend > 0 && divisor < 0) || (dividend < 0 && divisor > 0))
        {
            flag = -1;
        }
        if(dividend > 0) dividend = -dividend;
        if(divisor > 0) divisor = -divisor;
        int res = div(dividend, divisor);

        return flag>0 ? res : -res;

    }

    int div(int a, int b)
    {
        if(a > b) return 0;
        int count = 1;
        int tb = b;
        while((a-tb) <= tb)
        {
            count = count + count;
            tb = tb + tb;
        }
        return count + div(a-tb, b);
    }
};