SPOJ Adding Reversed Numbers

 #include<cstdio>
#include<iostream>
#include<algorithm>
#include<cmath>

#define sf scanf
#define pf printf

using namespace std;

typedef unsigned long long ull;
typedef long L;

ull reverse_num(ull n)
{
    ull a=n,add=0,b=n;

    while(a>0)
    {
        a%=10;
        add = a+(add*10);
        b/=10;
        a=b;
    }

    return add;
}

int main()
{
    L t;
    sf("%ld",&t);

    while(t--)
    {
        ull x,y;
        sf("%llu %llu",&x,&y);

        ull result = reverse_num(x) + reverse_num(y);

        pf("%llu\n",reverse_num(result));
    }

    return 0;
}