lintcode_两数相加不使用+号--采用位运算实现加法

#include<iostream>
using namespace std;

int add(int a , int b)  
{  
    int sum = a;  
      
    /*直到进位的结果为0*/  
    while(b != 0)  
    {  
        sum = a ^ b; /*不考虑进位的和*/  
        b = (a & b) << 1; /*只考虑进位的产生值*/  
        a = sum;  
    }//while  
    return sum;  
}  
int main()
{	
	int x, y,z;
	cin>>x>>y;
	z = add(x,y);
	cout<<z<<endl;
}