奶牛问题,别人写的,自己试了一下.

  1 using System;
  2 using System.Collections.Generic;
  3 using System.Linq;
  4 using System.Text;
  5 
  6 namespace CowCount
  7 {
  8     public class Cow
  9     {
 10         public int Age { get; set; }
 11         public int Generation { get; set; }
 12         public int Id { get; set; }
 13         public int ParentId { get; set; }
 14 
 15         public Cow() { }
 16 
 17         public Cow(int age, int generation, int id, int parentId)
 18         {
 19             this.Age = age;
 20             this.Generation = generation;
 21             this.Id = id;
 22             this.ParentId = parentId;
 23         }
 24     }
 25     class Program
 26     {
 27         static List<Cow> listCows = new List<Cow>();
 28         static int maxYear = 20;
 29         public static void GetBirth(int year)
 30         {
 31             List<Cow> listBornCows = new List<Cow>(); //添加新生的奶牛
 32             Cow firstCow = new Cow(1, 1, 1, 0);
 33             listCows.Add(firstCow);
 34             for (int i = 0; i < year; i++)
 35             {
 36                 foreach (Cow item in listCows)
 37                 {
 38                     item.Age++; //年龄自增
 39                     if (item.Age > 4)
 40                     {
 41                         Cow birth = new Cow(1,item.Generation + 1, listCows.Count + 1, item.Id);
 42                         listBornCows.Add(birth); //添加新生的奶牛
 43                     }
 44                 }
 45                 listCows.AddRange(listBornCows);
 46                 listBornCows.Clear();
 47             }
 48         }
 49 
 50         public static List<Cow> GetCowByParentId(int parentId)
 51         {
 52             List<Cow> result = new List<Cow>();
 53             foreach (Cow item in listCows)
 54             {
 55                 if (item.ParentId == parentId)
 56                     result.Add(item);
 57             }
 58             return result;
 59         }
 60 
 61         public static void ShowCows()
 62         {
 63             int count = 0;
 64             if (listCows != null)
 65             {
 66                 count = listCows.Count;
 67             }
 68             Console.WriteLine(string.Format("After 20 years,cows count:{0}", count.ToString()));
 69 
 70             //按照所属于母亲显示对应奶牛数
 71             int maxParentId = 0;
 72             if (listCows.Count > 0)
 73             {
 74                 listCows.Sort(delegate(Cow left, Cow right) { return right.ParentId.CompareTo(left.ParentId); });
 75                 maxParentId = listCows[0].ParentId;
 76             }
 77             for (int i = 0; i < maxParentId; i++)
 78             {
 79                 List<Cow> listModels = GetCowByParentId(i);
 80                 Console.WriteLine(string.Format("Cow_{0}'s children as follows:",i));
 81                 if(listModels.Count == 0)
 82                 {
 83                     Console.WriteLine("Has no any child!");
 84 
 85                 }
 86                 else
 87                 {
 88                     foreach (Cow item in listModels)
 89                     {
 90                         Console.WriteLine(string.Format("Age:{0},Id:{1},Generation:{2}", item.Age, item.Id, item.Generation));
 91                     }
 92                 }
 93             }
 94         }
 95         static void Main(string[] args)
 96         {
 97             GetBirth(maxYear);
 98             Console.WriteLine(listCows.Count);
 99             //ShowCows();
100             Console.ReadLine();
101         }
102     }
103 }
104