Submission

Score: 100

User: Pera

Problemset: Fibonacci Croissant

Language: cpp

Time: 0.002 second

Submitted On: 2025-09-04 09:02:05

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

int main() {
    ios_base::sync_with_stdio(false);
    
    int n;
    cin >> n;
    
    long long sum = 0;
    if (n >= 1) {
        sum = 1;  
        long long currfibo = 1;
        long long prevfibo = 1;
        for (int i = 2; i <= n; ++i) {
            sum += currfibo;
            long long newfibo = currfibo + prevfibo;
            prevfibo = currfibo;
            currfibo = newfibo;
        }
    }
    cout << sum << '\n';
    return 0;
}