int sum(int a,int b)
{
    if(a==0)return b;
    if(b==0)return a;
    return sum((a&b)<<1,a^b);
}

Wow！so cool！！！

so,cool. help me !
my email:mronoal@163.com
thanks!

oooo  it's very  task.
But does not work.
Why?


-------------------

#include<iostream>
using namespace std;
int main()
{
int a,b;

cout<<"a=";cin>>a;
cout<<"b=";cin>>b;
cout<<a+b<<endl;
system("pause");
}




Why it's have a mistakes

Because you were asked to output only the sum of A and B, and NOT "a=" and "b=". A good thing is to read FAQ before starting to solve problems.