Even Fibonacci numbers

_{This problem is a programming version of Problem 2 from projecteuler.net}

Find the fibonacci series with the last element just equal to or less then the given $N$. Then sum up all the even valued terms in the series.

Code

C++

#include <bits/stdc++.h>
using namespace std;

int main() {
    int tc;
    cin >> tc;

    while (tc--) {
        long long n;
        cin >> n;
        long long a = 0, b = 1, c;
        long long res = 0;
        while (1) {
            c = a + b;
            if (c > n) break;
            if (c % 2 == 0) res += c;
            a = b;
            b = c;
        }
        cout << res << "\n";
    }
}