EvenFibonacciNumbers.cpp

#include <map>
#include <set>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <string>
#include <bitset>
#include <cstdio>
#include <limits>
#include <vector>
#include <climits>
#include <cstring>
#include <cstdlib>
#include <fstream>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <unordered_map>

using namespace std;

int main(){
    int t;
    cin >> t;
    for(int a0 = 0; a0 < t; a0++){
        long n;
        cin >> n;
        long long int f1 = 1,f2 = 2,f = 0, sum = 0;
        while(f1 < n)
        {
            if(f1 % 2 == 0)
            {
                sum += f1;
            }
            f = f1 + f2;
            f1 = f2;
            f2 = f;
            //cout << f1 << endl;
        }
        cout << sum << endl;
    }   return 0;
}