LeetCode: Divide Two Integers

很多bug还不清楚。。用了网上答案

 1 class Solution {

 2 public:

 3     int divide(int dividend, int divisor) {

 4         // Start typing your C/C++ solution below

 5         // DO NOT write int main() function

 6         bool isnegtive = false;

 7         int multiply = 0;

 8         long long a = dividend;

 9         long long b = divisor;

10         if (a < 0) {

11             a = -a;

12             isnegtive = !isnegtive;

13         }

14         if (b < 0) {

15             b = -b;

16             isnegtive = !isnegtive;

17         }

18         while (b << multiply <= a) {

19             multiply++;

20         }

21         int ret = 0;

22         for (int i = multiply-1; i >= 0; i--) {

23             if (b << i <= a) {

24                 ret = ret | (1 << i);

25                 a -= b << i;

26             }

27         }

28         if (isnegtive) ret = -ret;

29         return ret;

30     }

31 };