农夫养牛问题，四种方法

来源：互联网发布：怎样查看淘宝价格曲线编辑：程序博客网时间：2024/04/30 10:13

Code:

namespace AsyncCMdObjectApp
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("请输入年份:");
int n = Convert.ToInt32(Console.ReadLine());
Console.Write("/r最终有" + Calculate(n) + "头牛/n");
Console.Write("/r最终有" + Recursion(n) + "头牛/n");
Console.Write("/r最终有" + FIb(n) + "头牛/n");
countnum(n + 1);
}
//方法一
static int FIb(int year)
{
if (year == 1 || year == 2 || year == 3)
return 1;
else
{
return FIb(year - 1) + FIb(year - 3);
}
}
//方法二
static int Calculate(int year) //非递归
{
int Cow2 = 1;
int Cow1 = 0;
int Cow0 = 0;
for (int i = 1; i < year; i++)
{
int t = Cow0;
Cow0 += Cow1;
Cow1 = Cow2;
Cow2 = t;
}
return Cow0 + Cow1 + Cow2;
}
//方法三
static int Recursion(int year)//递归
{
int c = 1;
for (int i = 1; i <= year; i++)
{
if (i > 3)
c += Recursion(year - i + 1);
}
return c;
}
//方法四（最初）
private static void countnum(int n)
{
//每年牛的总数
int[] sum = new int[n];
//当年老牛的数量（明年可以生孩子的牛）
int[] oldcow = new int[n];
//当年2岁大的牛的数量
int[] cow2 = new int[n];
//当年1岁大的牛的数量
int[] cow1 = new int[n];
//当年0岁大的牛的数量
int[] cow0 = new int[n];
//如果年份小于等于三，返回1
if (n > 2)
{
//初始化前三年各个数组数量
sum[0] = 1; sum[1] = 1; sum[2] = 1;
oldcow[0] = oldcow[1] = oldcow[2] = 0;
cow2[0] = 0; cow2[1] = 0; cow2[2] = 1;
cow1[0] = 0; cow1[1] = 1; cow1[2] = 0;
cow0[0] = 1; cow0[1] = 0; cow0[2] = 0;
int year = 3;
while (year < n)
{
//下一年牛总数
sum[year] = sum[year - 1] + oldcow[year - 1];
//下一年的老牛
oldcow[year] = oldcow[year - 1] + cow2[year - 1];
//下一年2岁大的牛数量
cow2[year] = cow1[year - 1];
//下一年1岁大的牛数量
cow1[year] = cow0[year - 1];
//下一年0岁大的牛数量
cow0[year] = oldcow[year];
year++;
}
}
for (int k = 1; k < n; k++)
Console.WriteLine("第{0}年共有{1}头牛", k, sum[k]);
}
}
}

第五种方法面向对象的方法

Code:

public static class store
{
public static ArrayList list = new ArrayList();
}
class Cow
{
int age = 0;
public void play()
{
age++;
if (age > 3)
{
store.list.Add(new Cow());
}
}
}
static void Process(int n)
{
if (n <= 3)
Console.WriteLine("第{0}年共有1头牛", n);
else
{
for (int i = 1; i < n+ 1; i++)
{
ArrayList list_ = store.list;
if (i == 1)
{
store.list.Add(new Cow());
}
for (int j = 0; j < list_.Count; j++)
{
Cow c = (Cow)list_[j];
c.play();
}
Console.WriteLine("第{0}年共有{1}头牛", i, list_.Count);
}
}
}