【Leetcode】Divide Two Integers

 1 class Solution {
 2 public:
 3     int divide(int dividend, int divisor) {
 4         long long a = dividend < 0 ? -(long long)dividend : dividend;
 5         long long b = divisor < 0 ? -(long long)divisor : divisor;
 6         bool sign = (dividend >= 0 && divisor >= 0) || 
 7                     (dividend <= 0 && divisor <= 0);
 8         long long ans = 0;
 9         while (a >= b) {
10             long long c = b;
11             for (int i = 0; c <= a; c = c << 1, ++i) {
12                 a -= c;
13                 ans += (1 << i);
14             }
15         }
16         return sign ? ans : -ans;
17     }
18 };