> A+B 做法简单，耗时很少
> #include<cstdio>
> #include<cstdlib>
> #include<ctime>
> using namespace std;
> int main(){
>     srand(time(0)*time(0));
>     int a,b;long long l=0,r=(1<<31)-1,ans;
>     scanf("%d%d",&a,&b);
>     while(1){
>         ans=(rand()*rand())%r+l;
>         if(ans>a+b)r=ans-l;
>         else if(ans<a+b)l=ans;
>         else{printf("%lld\n",ans);return 0;}
>     }
> }
> 祝你在POJ快乐！

Orz神人啊。。。。。