Submission

Score: 100

User: kenmuay

Problemset: อนุกรม

Language: cpp

Time: 0.002 second

Submitted On: 2025-10-13 15:15:27

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

unsigned long long fibo(int x){
    if(x<=2) return 1;
    return fibo(x-1)+fibo(x-2);
}
int main(){
    int n;
    cin >> n;
    unsigned long long n1=1,n2=1,n3;
    if(n<=2) {
        cout << 1;
        return 0;
    }
    for(int i=3; i<=n; i++){
        n3=n1+n2;
        n1=n2;
        n2=n3;
    }
    cout << n3;
    return 0;
}