1、题目

 

Calculate the sum of two integers a and b, but you are not allowed to use the operator + and -.

Example:
Given a = 1 and b = 2, return 3.

Credits:
Special thanks to @fujiaozhu for adding this problem and creating all test cases.

 

 

 

 

2、代码实现

 

public class Solution {public int getSum(int a, int b) {while(b != 0)  {  int tmp =(a & b) << 1; //a是每次相加,相当于和a = a ^ b;//b相当于是进位b = tmp;}  return a;  }
}