371. Sum of Two Integers

static int wing=[]()
{
    std::ios::sync_with_stdio(false);
    cin.tie(NULL);
    return 0;
}();

class Solution 
{
public:
    int getSum(int a, int b) 
    {
        return b==0?a:getSum(a^b, (a&b)<<1);
    }
};

就是位操作，原理描述起来有点费劲，自行百度吧