Fibonacci Sum of Large Numbers(Only Last Digit to be Printed)

Question

I have been trying to come out with a solution regarding the problem of finding the last digit of the sum of large n Fibonacci series. I have been able to pass several test

Answer 1

For your function removing the array.

#include "stdafx.h"
#include 
using namespace std;
int calc_fib(long long int n) {

    int fibzero = 0;
    int fibone = 1;
    int fibnext;
    long long int res = 1;
    for (long long int i = 2; i <= n; i++) {

        fibnext = (fibone + fibzero) % 10;
        fibzero = fibone;
        fibone = fibnext;
        res = res + fibnext;
    }
    return (res % 10);
}

int main() 
{
    long long int n = 0;
    std::cin >> n;

    std::cout << calc_fib(n) << '\n';
    return 0;
}