Given a number *n* as input, the *fib_list()* algorithm is fast and good enough to print out the *n*th number of Fibonacci's sequence.

fibonacci.cpp

/*
Fibonacci number
Code by Erick Giffoni - University of Brasilia, Brazil (UnB)
*/

#include <iostream>
#include <vector>

int fib_naive(int n){
    if (n <=1) return n;
    else return fib_naive(n-1) + fib_naive(n-2);
}

int fib_list(int n){
    if(n <= 1) return n;
    std::vector <int> fib(n+1);
    fib[0] = 0;
    fib[1] = 1;
    for (int i=2; i<=n; i++){
        fib[i] = fib[i-1] + fib[i-2];
    }//end for
    return fib[n];
}

int main(){

    int n;
    std::cin >> n;
    std::cout << fib_list(n) << "\n";

    return 0;
}