利用递归的算法计算累加求和与阶乘

Question

Answer 1

int f(int n)
{
    if (n == 1) return 1;
    return n + f(n - 1);
}

int main()
{
    // 测试n=5
    int sum = f(5);
    cout << sum << endl;
    return 0;
}