View Code of Problem 23

#include <iostream>

using namespace std;

const int MAXN = 91;

long long arr[MAXN];

int main() {
    arr[0] = 0;
    arr[1] = 1;
    arr[2] = 2;
    for (int i = 3; i < MAXN; ++i) {
        arr[i] = arr[i - 2] + arr[i - 1];
    }

    int n;
    while (cin >> n) {
        if (n == 0)
            break;

        cout << arr[n] << endl;
    }
}