[递归]母牛的故事

解题思路:

注意事项:

参考代码:

#include<bits/stdc++.h>

using namespace std;

int main () {

    int cow[56] = {0,1,2,3,4};

    for(int i = 4; i < 55; i ++) cow[i] = cow[i-1] + cow[i-3];

    int n;

    while(scanf("%d", &n) && n) cout << cow[n] << endl;

    return 0;

}