201771010120 苏浪浪 《面向对象程序设计（java）》第11周学习总结

实验十一   集合

1、实验目的与要求

(1) 掌握Vetor、Stack、Hashtable三个类的用途及常用API；

(2) 了解java集合框架体系组成；

(3) 掌握ArrayList、LinkList两个类的用途及常用API。

(4) 了解HashSet类、TreeSet类的用途及常用API。

(5)了解HashMap、TreeMap两个类的用途及常用API；

(6) 结对编程（Pair programming）练习，体验程序开发中的两人合作。

2、实验内容和步骤

实验1： 导入第9章示例程序，测试程序并进行代码注释。

测试程序1：

l 使用JDK命令运行编辑、运行以下三个示例程序，结合运行结果理解程序；

l 掌握Vetor、Stack、Hashtable三个类的用途及常用API。 

//示例程序1

import java.util.Vector;

class Cat {

private int catNumber;

Cat(int i) {

catNumber = i;

}

void print() {

System.out.println("Cat #" + catNumber);

}

}

class Dog {

private int dogNumber;

Dog(int i) {

dogNumber = i;

}

void print() {

System.out.println("Dog #" + dogNumber);

}

}

public class CatsAndDogs {

public static void main(String[] args) {

Vector cats = new Vector();

for (int i = 0; i < 7; i++)

cats.addElement(new Cat(i));

cats.addElement(new Dog(7));

for (int i = 0; i < cats.size(); i++)

((Cat) cats.elementAt(i)).print();

}

}

//示例程序2

import java.util.*;

public class Stacks {

static String[] months = { "1", "2", "3", "4" };

public static void main(String[] args) {

Stack stk = new Stack();

for (int i = 0; i < months.length; i++)

stk.push(months[i]);

System.out.println(stk);

System.out.println("element 2=" + stk.elementAt(2));

while (!stk.empty())

System.out.println(stk.pop());

}

}

//示例程序3

import java.util.*;

class Counter {

int i = 1;

public String toString() {

return Integer.toString(i);

}

}

public class Statistics {

public static void main(String[] args) {

Hashtable ht = new Hashtable();

for (int i = 0; i < 10000; i++) {

Integer r = new Integer((int) (Math.random() * 20));

if (ht.containsKey(r))

((Counter) ht.get(r)).i++;

else

ht.put(r, new Counter());

}

System.out.println(ht);

}

}

1

package a;
    import java.util.Vector;

    class Cat {
        private int catNumber;

        Cat(int i) {
            catNumber = i;
        }

        void print() {
            System.out.println("Cat #" + catNumber);
        }
    }

    class Dog {
        private int dogNumber;

        Dog(int i) {
            dogNumber = i;
        }

        void print() {
            System.out.println("Dog #" + dogNumber);
        }
    }

    public class CatsAndDogs {
        public static void main(String[] args) {
            Vector cats = new Vector();
            Vector dogs = new Vector();
            for (int i = 0; i < 7; i++)
                cats.addElement(new Cat(i));
            cats.addElement(new Dog(7));
            for (int i = 0; i < cats.size(); i++)
                if(cats.elementAt(i)instanceof Cat)//做出判断能否被转换
                {
                ((Cat) cats.elementAt(i)).print();
        }
                else
                    ((Dog) cats.elementAt(i)).print();
    }
    }

2

package b;
import java.util.*;

public class Stacks {//stack是java里的一个集合类，用于模拟一个堆栈，存放的信息是后进的元素先出
    static String[] months = { "1", "2", "3", "4" };

    public static void main(String[] args) {
        Stack stk = new Stack();
        for (int i = 0; i < months.length; i++)
            stk.push(months[i]);
        System.out.println(stk);
        System.out.println("element 2=" + stk.elementAt(2));
        while (!stk.empty())
            System.out.println(stk.pop());
    }
}

3

package c;
import java.util.*;
class Counter {
    int i = 1;
    public String toString() {
        return Integer.toString(i);
    }
}
public class Statistics {
    public static void main(String[] args) {
        Hashtable ht = new Hashtable();//相当于array,里面可以存放大多数类型数据,在不知array的情况下用hashtable 比较方便；（键值类）
        for (int i = 0; i < 10000; i++) {
            Integer r = new Integer((int) (Math.random() * 20));//生成20以内的随机数
            if (ht.containsKey(r))//Hashtable常用方法，判断r是不是键值的一个方法
                ((Counter) ht.get(r)).i++;
            else
                ht.put(r, new Counter());
        }
        System.out.println(ht);
    }
}

测试程序2：

l 使用JDK命令编辑运行ArrayListDemo和LinkedListDemo两个程序，结合程序运行结果理解程序；

import java.util.*;

public class ArrayListDemo {

public static void main(String[] argv) {

ArrayList al = new ArrayList();

// Add lots of elements to the ArrayList...

al.add(new Integer(11));

al.add(new Integer(12));

al.add(new Integer(13));

al.add(new String("hello"));

// First print them out using a for loop.

System.out.println("Retrieving by index:");

for (int i = 0; i < al.size(); i++) {

System.out.println("Element " + i + " = " + al.get(i));

}

}

}

import java.util.*;

public class LinkedListDemo {

    public static void main(String[] argv) {

        LinkedList l = new LinkedList();

        l.add(new Object());

        l.add("Hello");

        l.add("zhangsan");

        ListIterator li = l.listIterator(0);

        while (li.hasNext())

            System.out.println(li.next());

        if (l.indexOf("Hello") < 0)   

            System.err.println("Lookup does not work");

        else

            System.err.println("Lookup works");

   }

}

package b;

import java.util.*;

public class ArrayListDemo {
    public static void main(String[] argv) {
        ArrayList al = new ArrayList();//ArrayList是实现了基于动态数组的数据结构;ArrayList要移动数据.
        // Add lots of elements to the ArrayList...
        al.add(new Integer(11));
        al.add(new Integer(12));
        al.add(new Integer(13));
        al.add(new String("hello"));
        // First print them out using a for loop.
        System.out.println("Retrieving by index:");
        for (int i = 0; i < al.size(); i++) {
            System.out.println("Element " + i + " = " + al.get(i));
        }
    }
}

2

package cc;

import java.util.*;
public class LinkedListDemo {
    public static void main(String[] argv) {
        LinkedList l = new LinkedList();//LinkedList基于链表的数据结构;LinkedList要移动指针
        l.add(new Object());
        l.add("Hello");
        l.add("zhangsan");
        ListIterator li = l.listIterator(0);
        while (li.hasNext())
            System.out.println(li.next());
        if (l.indexOf("Hello") < 0)   
            System.err.println("Lookup does not work");
        else
            System.err.println("Lookup works");
   }
}

 

l 在Elipse环境下编辑运行调试教材360页程序9-1，结合程序运行结果理解程序；

l 掌握ArrayList、LinkList两个类的用途及常用API。

package linkedList;

import java.util.*;

/**
 * This program demonstrates operations on linked lists.
 * @version 1.11 2012-01-26
 * @author Cay Horstmann
 */
public class LinkedListTest//LinkedList基于链表的数据结构;LinkedList要移动指针
{
   public static void main(String[] args)
   {
      List<String> a = new LinkedList<>();
      a.add("Amy");
      a.add("Carl");
      a.add("Erica");

      List<String> b = new LinkedList<>();
      b.add("Bob");
      b.add("Doug");
      b.add("Frances");
      b.add("Gloria");

      // merge the words from b into a

      ListIterator<String> aIter = a.listIterator();
      Iterator<String> bIter = b.iterator();

      while (bIter.hasNext())
      {
         if (aIter.hasNext()) aIter.next();
         aIter.add(bIter.next());
      }

      System.out.println(a);

      // remove every second word from b

      bIter = b.iterator();
      while (bIter.hasNext())
      {
         bIter.next(); // skip one element
         if (bIter.hasNext())
         {
            bIter.next(); // skip next element
            bIter.remove(); // remove that element
         }
      }

      System.out.println(b);

      // bulk operation: remove all words in b from a

      a.removeAll(b);

      System.out.println(a);
   }
}

 

测试程序3：

l 运行SetDemo程序，结合运行结果理解程序；

import java.util.*;

public class SetDemo {

    public static void main(String[] argv) {

        HashSet h = new HashSet(); //也可以 Set h=new HashSet()

        h.add("One");

        h.add("Two");

        h.add("One"); // DUPLICATE

        h.add("Three");

        Iterator it = h.iterator();

        while (it.hasNext()) {

             System.out.println(it.next());

        }

    }

}

l 在Elipse环境下调试教材365页程序9-2，结合运行结果理解程序；了解HashSet类的用途及常用API。

package set;

import java.util.*;

/**
 * This program uses a set to print all unique words in System.in.
 * @version 1.12 2015-06-21
 * @author Cay Horstmann
 */
public class SetTest
{
   public static void main(String[] args)
   {
      Set<String> words = new HashSet<>(); // HashSet是实现Set接口的一个类，
      long totalTime = 0;

      try (Scanner in = new Scanner(System.in))
      {
         while (in.hasNext())
         {
            String word = in.next();
            long callTime = System.currentTimeMillis();
            words.add(word);
            callTime = System.currentTimeMillis() - callTime;
            totalTime += callTime;
         }
      }

      Iterator<String> iter = words.iterator();
      for (int i = 1; i <= 20 && iter.hasNext(); i++)
         System.out.println(iter.next());
      System.out.println(". . .");
      System.out.println(words.size() + " distinct words. " + totalTime + " milliseconds.");
   }
}

l 在Elipse环境下调试教材367页-368程序9-3、9-4，结合程序运行结果理解程序；了解TreeSet类的用途及常用API。

package treeSet;

import java.util.*;

/**
 * This program sorts a set of item by comparing their descriptions.
 * @version 1.12 2015-06-21
 * @author Cay Horstmann
 */
public class TreeSetTest//TreeSet的存储原理：底层是通过二叉树的数据结构实现的，存储规则：左小右大，当添加元素的时候依靠的是元素的comparable方法来添加元素
{
   public static void main(String[] args)
   {
      SortedSet<Item> parts = new TreeSet<>();
      parts.add(new Item("Toaster", 1234));
      parts.add(new Item("Widget", 4562));
      parts.add(new Item("Modem", 9912));
      System.out.println(parts);

      NavigableSet<Item> sortByDescription = new TreeSet<>(
            Comparator.comparing(Item::getDescription));

      sortByDescription.addAll(parts);
      System.out.println(sortByDescription);
   }
}

测试程序4：

l 使用JDK命令运行HashMapDemo程序，结合程序运行结果理解程序；

import java.util.*;

public class HashMapDemo {

   public static void main(String[] argv) {

      HashMap h = new HashMap();

      // The hash maps from company name to address.

      h.put("Adobe", "Mountain View, CA");

      h.put("IBM", "White Plains, NY");

      h.put("Sun", "Mountain View, CA");

      String queryString = "Adobe";

      String resultString = (String)h.get(queryString);

      System.out.println("They are located in: " +  resultString);

  }

}

package treeSet;
import java.util.*;

public class HashMapDemo {

   public static void main(String[] argv) {

      HashMap h = new HashMap();//HashMap通过hashcode对其内容进行快速查找

      // The hash maps from company name to address.

      h.put("Adobe", "Mountain View, CA");

      h.put("IBM", "White Plains, NY");

      h.put("Sun", "Mountain View, CA");

      String queryString = "Adobe";

      String resultString = (String)h.get(queryString);

      System.out.println("They are located in: " +  resultString);

  }

}

l 在Elipse环境下调试教材373页程序9-6，结合程序运行结果理解程序；

package map;

import java.util.*;

/**
 * This program demonstrates the use of a map with key type String and value type Employee.
 * @version 1.12 2015-06-21
 * @author Cay Horstmann
 */
public class MapTest
{
   public static void main(String[] args)
   {
      Map<String, Employee> staff = new HashMap<>();//HashMap通过hashcode对其内容进行快速查找
      staff.put("144-25-5464", new Employee("Amy Lee"));
      staff.put("567-24-2546", new Employee("Harry Hacker"));
      staff.put("157-62-7935", new Employee("Gary Cooper"));
      staff.put("456-62-5527", new Employee("Francesca Cruz"));

      // print all entries

      System.out.println(staff);

      // remove an entry

      staff.remove("567-24-2546");

      // replace an entry

      staff.put("456-62-5527", new Employee("Francesca Miller"));

      // look up a value

      System.out.println(staff.get("157-62-7935"));

      // iterate through all entries

      staff.forEach((k, v) -> 
         System.out.println("key=" + k + ", value=" + v));
   }
}

l 了解HashMap、TreeMap两个类的用途及常用API。

          ：HashMap通过hashcode对其内容进行快速查找，而 TreeMap中所有的元素都保持着某种固定的顺序，如果你需要得到一个有序的结果你就应该使用TreeMap（HashMap中元素的排列顺序是不固定的）。

实验2：结对编程练习：

l 关于结对编程：以下图片是一个结对编程场景：两位学习伙伴坐在一起，面对着同一台显示器，使用着同一键盘，同一个鼠标，他们一起思考问题，一起分析问题，一起编写程序。

l 关于结对编程的阐述可参见以下链接：

http://www.cnblogs.com/xinz/archive/2011/08/07/2130332.html

http://en.wikipedia.org/wiki/Pair_programming

l 对于结对编程中代码设计规范的要求参考：

http://www.cnblogs.com/xinz/archive/2011/11/20/2255971.html

以下实验，就让我们来体验一下结对编程的魅力。

l 确定本次实验结对编程合作伙伴；

合作伙伴：马兴德（201771010117）；

l 各自运行合作伙伴实验九编程练习1，结合使用体验对所运行程序提出完善建议；

建议：

//修改后： File file = new File("身份证号.txt");（将文件放入该包中更好如前代码—）；

package Test;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Scanner;

public class Main{
    private static ArrayList<Student> studentlist;
    public static void main(String[] args) {
        studentlist = new ArrayList<>();
        Scanner scanner = new Scanner(System.in);
        File file = new File("D:\身份证号.txt");
       //修改后： File file = new File("身份证号.txt");（将文件放入该包中更好如前代码—）
        try {
            FileInputStream fis = new FileInputStream(file);
            BufferedReader in = new BufferedReader(new InputStreamReader(fis));
            String temp = null;
            while ((temp = in.readLine()) != null) {
                
                Scanner linescanner = new Scanner(temp);
                
                linescanner.useDelimiter(" ");    
                String name = linescanner.next();
                String number = linescanner.next();
                String sex = linescanner.next();
                String age = linescanner.next();
                String province =linescanner.nextLine();
                Student student = new Student();
                student.setName(name);
                student.setnumber(number);
                student.setsex(sex);
                int a = Integer.parseInt(age);
                student.setage(a);
                student.setprovince(province);
                studentlist.add(student);

            }
        } catch (FileNotFoundException e) {
            System.out.println("学生信息文件找不到");
            e.printStackTrace();
        } catch (IOException e) {
            System.out.println("学生信息文件读取错误");
            e.printStackTrace();
        }
        boolean isTrue = true;
        while (isTrue) {
            System.out.println("选择你的操作，输入正确格式的选项");
            System.out.println("a.字典排序");
            System.out.println("b.输出年龄最大和年龄最小的人");
            System.out.println("c.寻找老乡");
            System.out.println("d.寻找年龄相近的人");
            System.out.println("e.退出");
            String m = scanner.next();
            switch (m) {
            case "a":
                Collections.sort(studentlist);              
                System.out.println(studentlist.toString());
                break;
            case "b":
                 int max=0,min=100;
                 int j,k1 = 0,k2=0;
                 for(int i=1;i<studentlist.size();i++)
                 {
                     j=studentlist.get(i).getage();
                 if(j>max)
                 {
                     max=j; 
                     k1=i;
                 }
                 if(j<min)
                 {
                   min=j; 
                   k2=i;
                 }
                 
                 }  
                 System.out.println("年龄最大："+studentlist.get(k1));
                 System.out.println("年龄最小："+studentlist.get(k2));
                break;
            case "c":
                 System.out.println("老家?");
                 String find = scanner.next();        
                 String place=find.substring(0,3);
                 for (int i = 0; i <studentlist.size(); i++) 
                 {
                     if(studentlist.get(i).getprovince().substring(1,4).equals(place)) 
                         System.out.println("老乡"+studentlist.get(i));
                 }             
                 break;
                 
            case "d":
                System.out.println("年龄：");
                int yourage = scanner.nextInt();
                int near=agenear(yourage);
                int value=yourage-studentlist.get(near).getage();
                System.out.println(""+studentlist.get(near));
                break;
            case "e":
                isTrue = false;
                System.out.println("退出程序!");
                break;
                default:
                System.out.println("输入有误");

            }
        }
    }
        public static int agenear(int age) {      
        int j=0,min=53,value=0,k=0;
         for (int i = 0; i < studentlist.size(); i++)
         {
             value=studentlist.get(i).getage()-age;
             if(value<0) value=-value; 
             if (value<min) 
             {
                min=value;
                k=i;
             } 
          }    
         return k;         
      }

}

package Test;

public class Student implements Comparable<Student> {

    private String name;
    private String number ;
    private String sex ;
    private int age;
    private String province;
   
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getnumber() {
        return number;
    }
    public void setnumber(String number) {
        this.number = number;
    }
    public String getsex() {
        return sex ;
    }
    public void setsex(String sex ) {
        this.sex =sex ;
    }
    public int getage() {

        return age;
        }
        public void setage(int age) {
            // int a = Integer.parseInt(age);
        this.age= age;
        }

    public String getprovince() {
        return province;
    }
    public void setprovince(String province) {
        this.province=province ;
    }

    public int compareTo(Student o) {
       return this.name.compareTo(o.getName());
    }

    public String toString() {
        return  name+"	"+sex+"	"+age+"	"+number+"	"+province+"
";
    }    
}

l 各自运行合作伙伴实验十编程练习2，结合使用体验对所运行程序提出完善建议；

 建议：

1）、

 （2）、

                                                                                                                  

前边用了该程序以后后边子类不需要定义（b！=0）如上边1）和2）中：（2）明显多余；

l 采用结对编程方式，与学习伙伴合作完成实验九编程练习1；

package Test;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Scanner;

public class Main{
    private static ArrayList<Student> studentlist;
    public static void main(String[] args) {
        studentlist = new ArrayList<>();
        Scanner scanner = new Scanner(System.in);
        File file = new File("身份证号.txt");
              try {
            FileInputStream fis = new FileInputStream(file);
            BufferedReader in = new BufferedReader(new InputStreamReader(fis));
            String temp = null;
            while ((temp = in.readLine()) != null) {
                
                Scanner linescanner = new Scanner(temp);
                
                linescanner.useDelimiter(" ");    
                String name = linescanner.next();
                String number = linescanner.next();
                String sex = linescanner.next();
                String age = linescanner.next();
                String province =linescanner.nextLine();
                Student student = new Student();
                student.setName(name);
                student.setnumber(number);
                student.setsex(sex);
                int a = Integer.parseInt(age);
                student.setage(a);
                student.setprovince(province);
                studentlist.add(student);

            }
        } catch (FileNotFoundException e) {
            System.out.println("学生信息文件找不到");
            e.printStackTrace();
        } catch (IOException e) {
            System.out.println("学生信息文件读取错误");
            e.printStackTrace();
        }
        boolean isTrue = true;
        while (isTrue) {
            System.out.println("选择你的操作，输入正确格式的选项");
            System.out.println("a.字典排序");
            System.out.println("b.输出年龄最大和年龄最小的人");
            System.out.println("c.寻找老乡");
            System.out.println("d.寻找年龄相近的人");
            System.out.println("e.退出");
            String m = scanner.next();
            switch (m) {
            case "a":
                Collections.sort(studentlist);              
                System.out.println(studentlist.toString());
                break;
            case "b":
                 int max=0,min=100;
                 int j,k1 = 0,k2=0;
                 for(int i=1;i<studentlist.size();i++)
                 {
                     j=studentlist.get(i).getage();
                 if(j>max)
                 {
                     max=j; 
                     k1=i;
                 }
                 if(j<min)
                 {
                   min=j; 
                   k2=i;
                 }
                 
                 }  
                 System.out.println("年龄最大："+studentlist.get(k1));
                 System.out.println("年龄最小："+studentlist.get(k2));
                break;
            case "c":
                 System.out.println("老家?");
                 String find = scanner.next();        
                 String place=find.substring(0,3);
                 for (int i = 0; i <studentlist.size(); i++) 
                 {
                     if(studentlist.get(i).getprovince().substring(1,4).equals(place)) 
                         System.out.println("老乡"+studentlist.get(i));
                 }             
                 break;
                 
            case "d":
                System.out.println("年龄：");
                int yourage = scanner.nextInt();
                int near=agenear(yourage);
                int value=yourage-studentlist.get(near).getage();
                System.out.println(""+studentlist.get(near));
                break;
            case "e":
                isTrue = false;
                System.out.println("退出程序!");
                break;
                default:
                System.out.println("输入有误");

            }
        }
    }
        public static int agenear(int age) {      
        int j=0,min=53,value=0,k=0;
         for (int i = 0; i < studentlist.size(); i++)
         {
             value=studentlist.get(i).getage()-age;
             if(value<0) value=-value; 
             if (value<min) 
             {
                min=value;
                k=i;
             } 
          }    
         return k;         
      }

}

package Test;

public class Student implements Comparable<Student> {

    private String name;
    private String number ;
    private String sex ;
    private int age;
    private String province;
   
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getnumber() {
        return number;
    }
    public void setnumber(String number) {
        this.number = number;
    }
    public String getsex() {
        return sex ;
    }
    public void setsex(String sex ) {
        this.sex =sex ;
    }
    public int getage() {

        return age;
        }
        public void setage(int age) {
            // int a = Integer.parseInt(age);
        this.age= age;
        }

    public String getprovince() {
        return province;
    }
    public void setprovince(String province) {
        this.province=province ;
    }

    public int compareTo(Student o) {
       return this.name.compareTo(o.getName());
    }

    public String toString() {
        return  name+"	"+sex+"	"+age+"	"+number+"	"+province+"
";
    }    
}

l 采用结对编程方式，与学习伙伴合作完成实验十编程练习2。

package d;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.Scanner;


public class Demo {
    public static void main(String[] args) {

        Scanner in = new Scanner(System.in);
        Suanfa counter=new Suanfa();
        PrintWriter out = null;
        try {
            out = new PrintWriter("text.txt");
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        int sum = 0;

        
        
        for (int i = 0; i <10; i++) {
            int a = (int) Math.round(Math.random() * 100);
            int b = (int) Math.round(Math.random() * 100);
            int m= (int) Math.round(Math.random() * 3);

            
           switch(m)
           {
           case 0:
               System.out.println(a + "+" + b + "=");
               int d0 = in.nextInt();
               out.println(a + "+" + b + "=" + d0);
               if (d0 == counter.suanfa1(a, b)) {
                   sum += 10;
                   System.out.println("恭喜答案正确");
               } else {
                   System.out.println("抱歉，答案错误");
               }
               break;
           case 1:
               while (a < b) {
                   int x = a;
                   a = b;
                   b = x;
               }
               System.out.println(a + "-" + b + "=");
               int d1 = in.nextInt();
               out.println(a + "-" + b + "=" + d1);
               if (d1 == counter.suanfa2(a, b)) {
                   sum += 10;
                   System.out.println("恭喜答案正确");
               } else {
                   System.out.println("抱歉，答案错误");
               }
               break;
           case 2:
               System.out.println(a + "*" + b + "=");
               int d2 = in.nextInt();
               out.println(a + "*" + b + "=" + d2);
               if (d2 ==counter.suanfa3(a, b)) {
                   sum += 10;
                   System.out.println("恭喜答案正确");
               } else {
                   System.out.println("抱歉，答案错误");
               }
               break;
           case 3:
               while (b == 0 || a % b != 0) {
                   a = (int) Math.round(Math.random() * 100);
                   b = (int) Math.round(Math.random() * 100);
               }
               System.out.println(a + "/" + b + "=");
               int d3 = in.nextInt();
               out.println(a + "/" + b + "=" + d3);
               if (d3 == counter.suanfa4(a, b)) {
                   sum += 10;
                   System.out.println("恭喜答案正确");
               } else {
                   System.out.println("抱歉，答案错误");
               }
               break;

           }

       
}
        System.out.println("成绩"+sum);
        out.println("成绩:"+sum);
         out.close();

         
    }
    }

package d;
public class Suanfa<T> {
   private T a;
   private T b;
   public Suanfa() {
       a = null;
       b = null;
   }
  
   public Suanfa(T a, T b) {
       this.a = a;
       this.b = b;
   }
    public int   suanfa1(int a,int b)
    {
        return a+b;
    }
    public int   suanfa2(int a,int b)
    {
        return a-b;
    }
    public int   suanfa3(int a,int b)
    {
        return a*b;
    }
    public int   suanfa4(int a,int b)
    {
        if(b!=0)
        return a/b;
        else return 0;
    }

    
}

 

实验总结：通过本周学习以及老师和助教的帮助下：了解了HashMap、TreeMap两个类的用途；学习到了Vetor、Stack、Hashtable三个类的用途； 了解了java集合框架体系组成； 了解了HashSet类、TreeSet类的用途；在结对编程练习的过程中，我前边程序的不足得到一些完善；也了解到结对练习的好处。