23

23

代码如下——

#include<iostream>
using namespace std;
int fun(int n);
int main()
{int n, m;cin >> n;for (int i = 2; i <= n + 1; i++){cin >> m;cout << fun(m) << endl;}
}
int fun(int m)
{if (m == 0){return 0;}else if (m == 1){return 1;}else if (m == 2){return 2;}else if (m == 3){return 4;}else{returnfun(m - 1) + fun(m - 2) + fun(m - 3);}
}

运行结果如下——