Submission

Score: 100

User: Boeing12345

Problemset: อนุกรม

Language: cpp

Time: 0.004 second

Submitted On: 2026-09-23 17:35:04

#include <iostream>
#include <vector>
using namespace std;

int main() {
    int n;
    int i;
    long long k = 0;
    cin >> n;
    vector<long long> a;
    if (n == 0) {
        return 0;
    }

    if (n == 1) {
        cout << 1;
        return 0;
    }

    if (n == 2) {
        cout << 1;
        return 0;
    }

    if (n > 2 && n <= 90) {
        a.push_back(1);
        a.push_back(1);

        for (i = 3; i <= n; i++) {
            k = a[i - 2] + a[i - 3];
            a.push_back(k);
        }

        cout << a[n - 1];
    }
}