1004: [递归]母牛的故事

#include<bits/stdc++.h>
using namespace std;
int M[20]= {0,31,0,31,30,31,30,31,31,30,31,30,31};
bool isLeapyear(int y)
{
    if((y%4==0&&y%100!=0)||y%400==0)
    {
        return true;
    }
    return false;
}
bool check(int y)
{
    int m,d;
    m = (y%10)*10+((y/10)%10);
    d = ((y/100)%10)*10+((y/1000)%10);
    if(m==0||d==0||m>12)
    {
        return false;
    }
    if(m==2)
    {
        if(isLeapyear(y)){ M[2]=29;}
        else if(!isLeapyear(y)){M[2]=28;}
    }
    if(d<=M[m]){return true;}
    else{return false;}
}
int ReYear(int y)
{
    return (y%10)*1000+((y/10)%10)*100+((y/100)

#include<bits/stdc++.h>
using namespace std;
int M[20]= {0,31,0,31,30,31,30,31,31,30,31,30,31};
bool isLeapyear(int y)
{
    if((y%4==0&&y%100!=0)||y%400==0)
    {
        return true;
    }
    return false;
}
bool check(int y)
{
    int m,d;
    m = (y%10)*10+((y/10)%10);
    d = ((y/100)%10)*10+((y/1000)%10);
    if(m==0||d==0||m>12)
    {
        return false;
    }
    if(m==2)
    {
        if(isLeapyear(y)){ M[2]=29;}
        else if(!isLeapyear(y)){M[2]=28;}
    }
    if(d<=M[m]){return true;}
    else{return false;}
}
int ReYear(int y)
{
    return (y%10)*1000+((y/10)%10)*100+((y/100)

#include<iostream>
#include<vector>
using namespace std;
int main()
{
	while (true)
	{
		int n, num = 1;
		cin >> n;
		if (n == 0)
		{
			break;
		}
		vector<int>age;
		age.push_back(0);
		for (int i = 2; i <= n; i++)
		{
			int numplus = 0;
			for (int j = 0; j < num; j++)
			{
				age[j] += 1;
				if (age[j] >= 4)
				{
					numplus++;
				}
			}
			num = num + numplus + 1;
			for (int k = 0; k < (numplus + 1); k++)
			{
				age.push_back(0);
			}
		}	
			cout << num << endl;
		
	}
	return 0;

}为什么不可以

#include <iostream>
#include <string>
using namespace std;
#define N 55

int cow[N];
void b(int x);

int main()
{
	int n[N];
	b(N);
	int i=0;
	do
	{
		cin >> n[i];
	} while (n[i++] != 0);
	for (int j = 0; j < i-1; j++)
	{
		cout << cow[n[j]] << endl;
	}
	return 0;
}

void b(int x)
{
	for (int i = 1; i <= x; i++)
	{
		if (i < 4)
			cow[i] = i;
		else
			cow[i] = cow[i - 1] + cow[i - 3];
	}
}

uu们，为啥我这个不行
#include<iostream>
using namespace std;
long scn[5]={0};
long mcnum=1;
void cowreprouce(int year)
{   if(year<=0)
    return ;
    scn[4]+=scn[3];
    scn[3]=scn[2];
    scn[2]=scn[1];
    scn[1]=0;
    mcnum+=scn[4];
    scn[4]=0;
    scn[1]+=mcnum;
    if(--year>0)
    cowreprouce(year);
}
int main()
{
    int n;
    long res;
    cin>>n;
    if(n==0)
    return 0;
    n-=1;
    cowreprouce(n);
    res=mcnum+scn[1]+scn[2]+scn[3]+scn[4];
    cout<<res;
    return 0;
}

为什么这个不行？
#include<iostream>
using namespace std;
int f(int n);
int f(int n)
{
	if (n <=4)
	{
		return n;
	}
	else
	{
		return f(n - 1) + 1 + f(n - 4);
	}
}
int main()
{
	int n,num[100],i=1;
	cin >> n; num[0] = n;
	while (n != 0)
	{
		cin >> n;
		num[i] = n;
		i++;
	}
	cout << endl;
	for (int j = 0; j < i+1; j++)
	{
		if (num[j] != 0)
		{
			int sum = f(num[j]);
			cout << sum << endl;
		}
		else {
			break;
		}
	}
	system("pause");
	return 0;
}

"应题目要求使用递归:"这个代码不对，数组cow应该是={0,1,1,1,1}

#include<stdio.h>

int num(int n){
	if(n < 5) return n;
	else return num(n-1)+num(n-3);
}

int main(){
	int n;
	while(scanf("%d",&n) && n)
		printf("%d\n",num(n));
	}
	returrn 0;
}

注意要从n<5开始，这样时间才不会超