Submission

PPPPPPPPPP

Score: 100

User: 1234

Problemset: อนุกรม

Language: cpp

Time: 0.002 second

Submitted On: 2024-12-07 22:01:37

#include <iostream>
using namespace std;

long long fibonacci(int n){
    if(n == 1|| n == 2){
        return 1;
    }
    
    long long a = 1, b = 1, result;
    for (int i = 3; i<= n; i++){
        result = a + b;
        a = b;
        b = result;
    }
    return result;
}



int main(){
    
    
    int n;
    cin >> n;
    
    if(n <= 0 || n > 90) {
        return 1;   
    }
    
    long long result = fibonacci(n);
    cout << result;
}