Divide Two Integers

Divide two integers without using multiplication, division and mod operator.

 1 class Solution {
 2 public:
 3     int divide(int dividend, int divisor) {
 4         assert(divisor != 0);
 5         int res = 0;
 6         bool flag = (dividend > 0 && divisor > 0) || (dividend < 0 && divisor < 0);
 7         long long dividend1 = abs((long long)dividend);
 8         long long divisor1 = abs((long long)divisor);
 9         while(divisor1 <= dividend1) {
10             long long div = divisor1;
11             int quote = 1;
12             while((div << 1) <= dividend1) {
13                 div <<= 1;
14                 quote <<= 1;
15             }
16             dividend1 -= div;
17             res += quote;
18         }
19         return flag ? res : -res;
20     }
21 };