Szervusz, carlcolt!

/* test.cpp */
#include <iostream>
template <unsigned long N> struct Sum { enum { value = ((N%3)&&(N%5)?0:N) + Sum<N - 1>::value };};
template <> struct Sum<0> { enum { value = 0 };};
int main(){
  for(unsigned int j=0;j<10000;j++){
    unsigned long int x = Sum<10000>::value;
    std::cout<<x<<"\n";
  }
  return 0;
}
/* test2.cpp */
#include <iostream>

int main()
{
 for(unsigned int j=0;j<10000;j++){
   unsigned long int sum=0;for(int i=0;i<10000;i++)if((i%3==0)||(i%5==0))sum+=i;
   std::cout<<sum<<"\n";
  }
 return 0;
}