E02753:菲波那契数列

http://cs101.openjudge.cn/pctbook/E02753

//dp
#include <iostream>
using namespace std;

int main()
{
    int n;
    cin >> n;
    for (int i = 0; i < n; i++)
    {
        int input;
        cin >> input;
        if (input == 1 || input == 2)
        {
            cout << 1 << endl;
            continue;
        }
        int a = 1, b = 1;
        int tmp;
        for (int i = 0; i < input - 2; i++)
        {
            tmp = a + b;
            a = b;
            b = tmp;
        }
        cout << b << endl;
    }
    return 0;
}

//math
#include <iostream>
#include <cmath>
using namespace std;

int main()
{
    int n;
    cin >> n;
    for (int i = 0; i < n; i++)
    {
        int input;
        cin >> input;
        cout << (1 / sqrt(5)) * (pow((1 + sqrt(5)) / 2, input) - pow((1 - sqrt(5)) / 2, input)) << endl;
    }
    return 0;
}