[递归]母牛的故事-题解(C语言代码)

#include<stdio.h>

int main(){
	int n;
	int a[56] = { 0 };
	for (int i = 0; i < 3; i++)
		a[i] = i + 1;
	for (int i = 3; i < 56; i++)
		a[i] = a[i - 1] + a[i - 3];
	while (scanf("%d", &n) && n)
		printf("%d\n", a[n-1]);
} 

观察得知从第四年开始：a[i]=a[i-1]+a[i-3]