Even Fibonacci numbers

This 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

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#include <bits/stdc++.h>
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using namespace std;
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int main() {
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    int tc;
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    cin >> tc;
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    while (tc--) {
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        long long n;
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        cin >> n;
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        long long a = 0, b = 1, c;
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        long long res = 0;
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        while (1) {
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            c = a + b;
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            if (c > n) break;
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            if (c % 2 == 0) res += c;
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            a = b;
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            b = c;
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        }
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        cout << res << "\n";
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    }
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}

Give it a try first

Attempt the problem on HackerRank — the code will still be here.