C# Arraylist + struct 综合练习 枚举ENUE 递归

枚举类型

一组常量的组合，

在不制定任何索引的情况下，默认第一个字段从0开始，之后的依次+1 在指定了某个索引的情况下，之后的依次+1 若之前定义的某字段的索引指向了之后的某个默认字段，那么他俩完全相同

不需要初始化

Console.WriteLine(meiju.five);

//常量字段 Console.WriteLine((int)meiju.five);

//字段代表的值 Console.WriteLine(meiju.one);

//常量字段 Console.WriteLine((int)meiju.one);

//字段代表的值 Console.WriteLine(meiju.four);

//定义枚举类型时，等于之前的一个字段，那么就是等于那个字段

//定义枚举类型时，等于一个int的时候，他和他后面的索引+1

1，

Arraylist + struct 综合练习    数据的存放     数据的 提取     提取时注意格式转变           初始化

//定义一个结构体，存放关于车辆的几个信息
            //将所有车的信息都放入集合中
            //车型号               价格（W）    轴距 （mm）         油耗（L/100km）
            //宝马320Li           38              2920                        6.9
            //宝马520Li           43              3108                        7.2
            //宝马730Li            89              3210                       6.3
            //奥迪A4L35TFSI   31              2869                        6.2
            //奥迪A6L30TFSI   43              3012                        7.6
            //奥迪A8L45TFSI   89              3122                        8.1
            //奔驰C200L           35              2920                        6.1
            //奔驰E260L           48              3014                        6.7
            //奔驰S320L           93              3165                        8

  class Program
     {
                struct Car
         {
             public string name;
             public double price;
             public double zhou;
             public double you;
         }

         static void Main(string[] args)
         {

  #region            购车例题
             ArrayList caral=new ArrayList();
             Car a1=new Car();
             a1.name="宝马320Li";
             a1.price=;
             a1.zhou=;
             a1.you=6.9;
             caral.Add(a1);
            Car a2=new Car();
             a2.name="宝马520Li";
             a2.price=;
             a2.zhou=;
             a2.you=7.2;
             caral.Add(a2);

             Car a3=new Car();
             a3.name="宝马730Li";
             a3.price=;
             a3.zhou=;
             a3.you=6.3;
             caral.Add(a3);

             Car a4=new Car();
             a4.name="奥迪A4L35TFSI";
             a4.price=;
             a4.zhou=;
             a4.you=6.2;
             caral.Add(a4);

             Car a5=new Car();
             a5.name="奥迪A6L30TFSI";
             a5.price=;
             a5.zhou=;
             a5.you=7.6;
             caral.Add(a5);

             Car a6=new Car();
             a6.name="奥迪A8L45TFSI";
             a6.price=;
             a6.zhou=;
             a6.you=8.1;
             caral.Add(a6);

             Car a7=new Car();
             a7.name="奔驰C200L";
             a7.price=;
             a7.zhou=;
             a7.you=6.1;
             caral.Add(a7);

             Car a8=new Car();
             a8.name="奔驰E260L";
             a8.price=;
             a8.zhou=;
             a8.you=6.7;
             caral.Add(a8);

             Car a9=new Car();
             a9.name="奔驰S320L";
             a9.price=;
             a9.zhou=;
             a9.you=;
             caral.Add(a9);
             //所有在售车辆中最便宜的
             for (int i = ; i < ;i++ )
             {
                 for (int j = i + ; j < ;j++ )
                 {
                     Car q1 =(Car)caral[i];
                     Car q2 = (Car)caral[j];
                     if(q1.price>q2.price)
                     {
                         object zhong = caral[i];
                         caral[i] = caral[j];
                         caral[j] = zhong;
                     }
                 }
             }
             Car cheap = (Car)caral[];
             Console.WriteLine("最便宜的是{0}，价格{1}，轴距{2}，油耗{3}。",cheap.name,cheap.price,cheap.zhou,cheap.you);

             Console.WriteLine("---------------------------------------------------------------------------------------------");

             //求宝马中最便宜的车型是什么，所有信息列出
             for (int i = ; i < ;i++ )
             {
                 Car baocheap = (Car)caral[i];
                 if(baocheap.name.Contains("宝马"))
                 {
                     Console.WriteLine("宝马车中最便宜的是{0}，价格{1}，轴距{2}，油耗{3}。", baocheap.name, baocheap.price, baocheap.zhou, baocheap.you);
                     break;
                 }
             }
             Console.WriteLine("---------------------------------------------------------------------------------------------");

             //选个轴距最长的
             for (int i = ; i < ; i++)
             {
                 for (int j = i + ; j < ; j++)
                 {
                     Car q1 = (Car)caral[i];
                     Car q2 = (Car)caral[j];
                     if (q1.zhou < q2.zhou)
                     {
                         object zhong = caral[i];
                         caral[i] = caral[j];
                         caral[j] = zhong;
                     }
                 }
             }
             Car zhou = (Car)caral[];
             Console.WriteLine("轴距最长的车是{0}，价格{1}，轴距{2}，油耗{3}。", zhou.name, zhou.price, zhou.zhou, zhou.you);
             Console.WriteLine("---------------------------------------------------------------------------------------------");

             //选个轴距最长的，必须是奔驰
             for (int i = ; i < ; i++)
             {
                 Car zhouben = (Car)caral[i];
                 if (zhouben.name.Contains("奔驰"))
                 {
                     Console.WriteLine("奔驰车中轴距最长的是{0}，价格{1}，轴距{2}，油耗{3}。", zhouben.name, zhouben.price, zhouben.zhou, zhouben.you);
                     break;
                 }
             }
             Console.WriteLine("---------------------------------------------------------------------------------------------");

             //想要一辆油耗最低的车
             for (int i = ; i < ; i++)
             {
                 for (int j = i + ; j < ; j++)
                 {
                     Car q1 = (Car)caral[i];
                     Car q2 = (Car)caral[j];
                     if (q1.you > q2.you)
                     {
                         object zhong = caral[i];
                         caral[i] = caral[j];
                         caral[j] = zhong;
                     }
                 }
             }
             Car youdi = (Car)caral[];
             Console.WriteLine("油耗最低的车辆是{0}，价格{1}，轴距{2}，油耗{3}。", youdi.name, youdi.price, youdi.zhou, youdi.you);
             Console.WriteLine("---------------------------------------------------------------------------------------------");

             //想要一辆油耗最低的奥迪车
             for (int i = ; i < ; i++)
             {
                 Car zhouben = (Car)caral[i];
                 if (zhouben.name.Contains("奥迪"))
                 {
                     Console.WriteLine("奥迪车中油耗最低的是{0}，价格{1}，轴距{2}，油耗{3}。", zhouben.name, zhouben.price, zhouben.zhou, zhouben.you);
                     break;
                 }
             }
             Console.WriteLine("---------------------------------------------------------------------------------------------");

             //我只有50万，看看能买什么车
             int biao = ;
             for (int i = ; i < ;i++ )
             {
                 Car diwushi = (Car)caral[i];
                 if(diwushi.price<=)
                 {
                     biao++;
                     Console.WriteLine("第{0}辆：{1}，价格{2}，轴距{3}，油耗{4}。",biao,diwushi.name,diwushi.price,diwushi.zhou,diwushi.you);
                 }
             }
             Console.WriteLine("---------------------------------------------------------------------------------------------");

             //我只需要60万以上的车，列出来所有车型和所有信息
             int biao1 = ;
             for (int i = ; i < ; i++)
             {
                 Car diwushi = (Car)caral[i];
                 if (diwushi.price > )
                 {
                     biao1++;
                     Console.WriteLine("第{0}辆：{1}，价格{2}，轴距{3}，油耗{4}。", biao1, diwushi.name, diwushi.price, diwushi.zhou, diwushi.you);
                 }
             }
             Console.WriteLine("---------------------------------------------------------------------------------------------");

             //轴距必须超过3m，列列表
             int biao2 = ;
             for (int i = ; i < ; i++)
             {
                 Car diwushi = (Car)caral[i];
                 if (diwushi.zhou>)
                 {
                     biao2++;
                     Console.WriteLine("第{0}辆：{1}，价格{2}，轴距{3}，油耗{4}。", biao2, diwushi.name, diwushi.price, diwushi.zhou, diwushi.you);
                 }
             }
             Console.WriteLine("---------------------------------------------------------------------------------------------");

             //油耗在8.5以下都行，列列表
             int biao3 = ;
             for (int i = ; i < ; i++)
             {
                 Car diwushi = (Car)caral[i];
                 if (diwushi.you<=8.5)
                 {
                     biao3++;
                     Console.WriteLine("第{0}辆：{1}，价格{2}，轴距{3}，油耗{4}。", biao3, diwushi.name, diwushi.price, diwushi.zhou, diwushi.you);
                 }
             }
             Console.WriteLine("---------------------------------------------------------------------------------------------");

             //我不在乎油耗，要油耗最高的车
             for (int i = ; i < ; i++)
             {
                 for (int j = i + ; j < ; j++)
                 {
                     Car q1 = (Car)caral[i];
                     Car q2 = (Car)caral[j];
                     if (q1.you < q2.you)
                     {
                         object zhong = caral[i];
                         caral[i] = caral[j];
                         caral[j] = zhong;
                     }
                 }
             }
             Car yougao = (Car)caral[];
             Console.WriteLine("油耗最高的车辆是{0}，价格{1}，轴距{2}，油耗{3}。", yougao.name, yougao.price, yougao.zhou, yougao.you);

             #endregion

购车 方法1

2.
public ArrayList al = new ArrayList();      注意位置

//输入班级人数，输入学生的学号、姓名、语数英分数
            //存入结构体
            //然后求语文分数为最高分的两个学生的所有信息
            //数学最高分的两个学生的信息
            //英语平均分

 class Program
    {
        #region    成绩
        //结构体是自定义类型，可以当做数据类型来使用
        struct Student
        {
            public int code;
            public string name;
            public Score score;
        }
        struct Score
        {
            public double yufen;
            public double shufen;
            public double yingfen;
        }
        public ArrayList al = new ArrayList();   *******

  static void Main(string[] args)
        {            #region                        班级排名

            //输入班级人数，输入学生的学号、姓名、语数英分数
            //存入结构体
            //然后求语文分数为最高分的两个学生的所有信息
            //数学最高分的两个学生的信息
            //英语平均分
            Console.Write("请输入班级人数：");
            int a = int.Parse(Console.ReadLine());
            Program hs = new Program();
            for (int i = ; i < a;i++ )
            {
                Student st = new Student();
                Console.Write("请输入第{0}个学生的学号：",(i+));
                st.code = int.Parse(Console.ReadLine());
                Console.Write("请输入第{0}个学生的姓名：", (i + ));
                st.name = Console.ReadLine();
                Console.Write("请输入第{0}个学生的语文分数：", (i + ));
                st.score.yufen = double.Parse(Console.ReadLine());
                Console.Write("请输入第{0}个学生的数学分数：", (i + ));
                st.score.shufen = double.Parse(Console.ReadLine());
                Console.Write("请输入第{0}个学生的英语分数：", (i + ));
                st.score.yingfen = double.Parse(Console.ReadLine());
                hs.al.Add(st);
            }
            Console.WriteLine("所有人员信息输入完毕！请按回车键继续！");
            Console.ReadLine();
            //然后求语文分数为最高分的两个学生的所有信息
            for (int i = ; i < a - ;i++ )
            {
                for (int j = i + ; j < a;j++ )
                {
                    Student st1 =(Student)hs.al[i];
                    Student st2 =(Student)hs.al[j];
                      if(st1.score.yufen<st2.score.yufen)
                      {
                          object zhong = hs.al[i];
                          hs.al[i] = hs.al[j];
                          hs.al[j] = zhong;
                      }
                }
            }
            Student yu1 = (Student)hs.al[];
            Student yu2 = (Student)hs.al[];
            Console.WriteLine("语文分数最高的第一个学生的学号：{0}，姓名：{1}，语文分数：{2}，数学分数：{3}，英语分数：{4}。",yu1.code,yu1.name,yu1.score.yufen,yu1.score.shufen,yu1.score.yingfen);
            Console.WriteLine("语文分数最高的第二个学生的学号：{0}，姓名：{1}，语文分数：{2}，数学分数：{3}，英语分数：{4}。", yu2.code, yu2.name, yu2.score.yufen, yu2.score.shufen, yu2.score.yingfen);
            //数学最高分的两个学生的信息
            for (int i = ; i < a - ; i++)
            {
                for (int j = i + ; j < a; j++)
                {
                    Student st1 = (Student)hs.al[i];
                    Student st2 = (Student)hs.al[j];
                    if (st1.score.shufen < st2.score.shufen)
                    {
                        object zhong = hs.al[i];
                        hs.al[i] = hs.al[j];
                        hs.al[j] = zhong;
                    }
                }
            }
            Student shu1 = (Student)hs.al[];
            Student shu2 = (Student)hs.al[];
            Console.WriteLine("数学分数最高的第一个学生的学号：{0}，姓名：{1}，语文分数：{2}，数学分数：{3}，英语分数：{4}。", shu1.code, shu1.name, shu1.score.yufen, shu1.score.shufen, shu1.score.yingfen);
            Console.WriteLine("数学分数最高的第二个学生的学号：{0}，姓名：{1}，语文分数：{2}，数学分数：{3}，英语分数：{4}。", shu2.code, shu2.name, shu2.score.yufen, shu2.score.shufen, shu2.score.yingfen);
            //英语平均分
            double sum = ;
            for (int i = ; i < hs.al.Count;i++ )
            {
                Student ying = (Student)hs.al[i];
                sum += ying.score.yingfen;
            }
            Console.WriteLine("班级英语平均分是："+(sum/a));
            #endregion

班级排名

3.递归

函数体内调用本函数自身，直到符合某一条件不再继续调用

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace 递归练习
{
    class Program
    {
        public int yang(int n)
        {
            int sum = ;
            if(n==)
            {
                return ;

            }
            sum =  * (yang(n + ) + );

            return sum;
        }

        static void Main(string[] args)
        {
            Program y = new Program();
            Console.Write("路过村字数量：");
            int n = int.Parse(Console.ReadLine());
            int sum = y.yang(n);
            Console.Write(sum);
            Console.ReadLine();

递归例题