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  • 东文财、赵栋《面向对象程序设计(java)》第十一周学习总结

    201771010106 东文财《面向对象程序设计(java)》第十一周

    实验时间 2018-11-8

    一:理论部分。

    1.数据结构:

    a.线性数据结构,如线性表、栈、队列、串、数组和文件。

    b.非线性数据结构,如树和图。

    1)所有数据元素在同一个线性表中必须是相同的数据类型。

    线性表按其存储结构可分为顺序表和链表。

    2)栈:也是一种特殊的线性表,是一种后进先出(LIFO)的结构。

    栈是限定仅在表尾进行插入和删除运算的线性表,表尾称为栈顶,表头称为栈底。

    3)队列:限定所有的插入只能在表的一端进行,而所有的删除都在表的另一端进行的线性表。是一种先进先出(FIFO)的结构。

    表中允许插入的一端称为队尾,允许删除的一端称为队头。

    2.集合:(容器)是一种包含多个元素并提供对所包含元素操作方法的类,其包含的元素可以由同一类型的对象组成,也可以由不同类型的对象组成。

    1)集合框架:JAVA集合类库的统一架构。

    2)集合类的作用(包含在java.util包中):提供一些基本数据结构的支持,如Vector、Hashtable、Stack等。

    3)集合类的特点:

    a.只容纳对象;

    b.集合类容纳的对象都是Object类的实例(一旦把一个对象置入集合类中,它的类信息将丢失)

    4)Vector类:类似长度可变的数组。它只能存放对象,其元素通过下标进行访问。

    5)Stack类(Vector的子类):它描述堆栈数据结构。(所有对象都有一个散列码,可以通过Object类的hashCode方法获得。)

    3.集合框架中的基本接口:

    a.Collection(构造类集框架的基础):集合层次中的根接口,JDK未提供这个接口的直接实现类。

    b.Set:不能包含重复的元素,即元素必须唯一。对象可能不是按存放的次序存放。(实 现 Set 接口的类有HashSet,TreeSet)

    c.List:有序的集合,可以包含重复的元素。提供了按索引访问的方式。实现它的类有ArrayList和LinkedLis(如ArrayList:能够自动增长容量的数组   .                       d.Map:Map接口映射唯一关键字到值。包含了key-value对。Map不能包含重复的key。SortedMap是一个按照升序排列key的Map。

    二:实验部分。

    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。

    1、实验目的与要求

    (1) 掌握VetorStackHashtable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ArrayListLinkList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HashMapTreeMap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:

    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;

    掌握VetorStackHashtable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);

    }

    }

    示例程序1:

    package qq;
    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 WW {
        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++) {
                if(cats.elementAt(i) instanceof Cat) {//instanceof指出对象是否是cat类
                    ((Cat) cats.elementAt(i)).print();    
                }
                //((Cat) cats.elementAt(i)).print();//程序有未检查异常
        
            else {
                ((Dog) cats.elementAt(i)).print();//判断后若不是则返回dog类
            }
        }
    }
    }

    实验结果:

    示例程序2:

    package qq;
    import java.util.*;
    public class Stzacks {
        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]);//入栈操作
            System.out.println(stk);
            System.out.println("element 2=" + stk.elementAt(2));
            //elementAt(2)该方法在没有list以前跟get方法的功能完全相同
            while (!stk.empty())
                System.out.println(stk.pop());//出栈操作
        }
    }

    实验结果:

    示例程序3:

    package qq;
    
    import java.util.*;
    
    class Counter {
        int i = 1;//权限
    
        public String toString() {
            return Integer.toString(i);
        }
    }
    public class WW {
        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));//random半开半闭区间0-19的数
                //Integer是int的封装类,将生成的数据转化成整型,让r去调用它
                if (ht.containsKey(r))
                    ((Counter) ht.get(r)).i++;//直接在类外部引用属性是因为i的访问权限是friendly
                //通过get方法通过键获得对应的value值
                else
                    ht.put(r, new Counter());//调用put方法使得哈希表创建一个新的键值对
            }
            System.out.println(ht);
        }
    }

    实验结果:

    测试程序2:

    使用JDK命令编辑运行ArrayListDemoLinkedListDemo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 qq;
    import java.util.*;
    public class WW {
        public static void main(String[] argv) {
            ArrayList al = new ArrayList();//ArrayList类生成一个数组由a1调用使用
            // Add lots of elements to the ArrayList...
            al.add(new Integer(11));
            //integer是与int不同的数据类型,往ArrayList中放东西时,像int这种内建类型是放不进去的。
            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));//已有list,可直接用get方法
            }
        }
    }

    实验结果:

    package qq;
    import java.util.*;
    public class LinkedListDemo {//以双向链表的形式完成操作
         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);//listIterator(迭代器)用来遍历集合
                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");
           }
    }

    实验结果:

    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;

    掌握ArrayListLinkList两个类的用途及常用API

    package qq;
    
    import java.util.*;
    
    /**
     * This program demonstrates operations on linked lists.
     * @version 1.11 2012-01-26
     * @author Cay Horstmann
     */
    public class WW
    {
       public static void main(String[] args)
       {
          List<String> a = new LinkedList<>();//创建一个泛型类型,使得a能引用它
          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();//遍历a中的所有元素,且a中元素为string类
          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);
       }
    }

    实验结果:

    测试程序3

    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());

            }

        }

    }

    package qq;
    import java.util.*;
    public class WW {
         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());
                }
         }
    }

    实验结果:

    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 qq;
    
    
    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 WW
    {
       public static void main(String[] args)
       {
          Set<String> words = new HashSet<>(); // HashSet implements Set
          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.");
       }
    }

    Elipse环境下调试教材367-368程序9-39-4,结合程序运行结果理解程序;了解TreeSet类的用途及常用API

    package qq;
    
    import java.util.*;
    
    /**
     * An item with a description and a part number.
     */
    public class ee implements Comparable<ee>
    {
       private String description;
       private int partNumber;
    
       /**
        * Constructs an item.
        * 
        * @param aDescription
        *           the item's description
        * @param aPartNumber
        *           the item's part number
        */
       public ee(String aDescription, int aPartNumber)
       {
          description = aDescription;
          partNumber = aPartNumber;
       }
    
       /**
        * Gets the description of this item.
        * 
        * @return the description
        */
       public String getDescription()
       {
          return description;
       }
    
       public String toString()
       {
          return "[description=" + description + ", partNumber=" + partNumber + "]";
       }
    
       public boolean equals(Object otherObject)
       {
          if (this == otherObject) return true;
          if (otherObject == null) return false;
          if (getClass() != otherObject.getClass()) return false;
          ee other = (ee) otherObject;
          return Objects.equals(description, other.description) && partNumber == other.partNumber;
       }
    
       public int hashCode()
       {
          return Objects.hash(description, partNumber);
       }
    
       public int compareTo(ee other)
       {
          int diff = Integer.compare(partNumber, other.partNumber);
          return diff != 0 ? diff : description.compareTo(other.description);
       }
    }
    package qq;
    
    
    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 WW
    {
       public static void main(String[] args)
       {
          SortedSet<ee> parts = new TreeSet<>();
          parts.add(new ee("Toaster", 1234));
          parts.add(new ee("Widget", 4562));
          parts.add(new ee("Modem", 9912));
          System.out.println(parts);
    
          NavigableSet<ee> sortByDescription = new TreeSet<>(
                Comparator.comparing(ee::getDescription));
    
          sortByDescription.addAll(parts);
          System.out.println(sortByDescription);
       }
    }

    实验结果|:

    测试程序4:

    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 qq;
    import java.util.*;
    public class WW {
         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";//访问指定的关键字Adobe
              String resultString = (String)h.get(queryString);
              System.out.println("They are located in: " +  resultString);
              
          }
    }

    实验结果:

    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;

    了解HashMapTreeMap两个类的用途及常用API。

    package qq;
    
    
    /**
     * A minimalist employee class for testing purposes.
     */
    public class WW
    {
       private String name;
       private double salary;
    
       /**
        * Constructs an employee with $0 salary.
        * @param n the employee name
        */
       public WW(String name)
       {
          this.name = name;
          salary = 0;
       }
    
       public String toString()
       {
          return "[name=" + name + ", salary=" + salary + "]";
       }
    }
    package qq;
    
    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 ee
    {
       public static void main(String[] args)
       {
          Map<String, WW> staff = new HashMap<>();
          staff.put("144-25-5464", new WW("Amy Lee"));
          staff.put("567-24-2546", new WW("Harry Hacker"));
          staff.put("157-62-7935", new WW("Gary Cooper"));
          staff.put("456-62-5527", new WW("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 WW("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));
       }
    }

    实验结果:

    实验2:结对编程练习:

    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。

     

    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

    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。

    确定本次实验结对编程合作伙伴;

    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;

    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 qq;
    import java.beans.Statement;
    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 WW {
    private static ArrayList<Statement> studentlist;
    public static void main(String[] args) {
    
            studentlist = new ArrayList<>();
            Scanner scanner = new Scanner(System.in);
            File file = new File("F:\java\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();
                    Statement student = new Statement(student, province, args);
                    ((Object) 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("找不到学生的信息文件");
                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, ");
                System.out.println("1.字典排序  ");
                System.out.println("2.输出年龄最大和年龄最小的人  ");
                System.out.println("3.寻找同乡  ");
                System.out.println("4.寻找年龄相近的人  ");
                System.out.println("5.退出 ");
                String m = scanner.next();
                switch (m) {
                case "1":
                    Collections.sort(studentlist);              
                    System.out.println(studentlist.toString());
                    break;
                case "2":
                     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 "3":
                     System.out.println("地址?");
                     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("同乡"+studentlist.get(i));
                     }             
                     break;
                     
                case "4":
                    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 "5 ":
                    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,ok=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;
                     ok=i;
                 } 
              }    
             return ok;         
          }
    }
    package qq;
    
    public class ee {
        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+"
    ";
            }    
        }
    
    
    }

    实验结果:

    package qq;
    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 Search{
    
    private static ArrayList<Person> Personlist1;
    public static void main(String[] args) {
    
    Personlist1 = new ArrayList<>();
    
    Scanner scanner = new Scanner(System.in);
    File file = new File("E:\面向对象程序设计Java\实验\实验六\身份证号.txt");
    
    try {
    FileInputStream F = new FileInputStream(file);
    BufferedReader in = new BufferedReader(new InputStreamReader(F));
    String temp = null;
    while ((temp = in.readLine()) != null) {
    
    Scanner linescanner = new Scanner(temp);
    
    linescanner.useDelimiter(" "); 
    String name = linescanner.next();
    String id = linescanner.next();
    String sex = linescanner.next();
    String age = linescanner.next();
    String place =linescanner.nextLine();
    Person Person = new Person();
    Person.setname(name);
    Person.setid(id);
    Person.setsex(sex);
    int a = Integer.parseInt(age);
    Person.setage(a);
    Person.setbirthplace(place);
    Personlist1.add(Person);
    
    }
    } catch (FileNotFoundException e) {
    System.out.println("查找不到信息");
    e.printStackTrace();
    } catch (IOException e) {
    System.out.println("信息读取有误");
    e.printStackTrace();
    }
    boolean isTrue = true;
    while (isTrue) {
    System.out.println("******************************************");
    System.out.println("1:按姓名字典顺序输出信息;");
    System.out.println("2:查询最大年龄与最小年龄人员信息;");
    System.out.println("3:按省份找你的同乡;");
    System.out.println("4:输入你的年龄,查询年龄与你最近人的信息;");
    System.out.println("5:退出");
    System.out.println("******************************************");
    int type = scanner.nextInt();
    switch (type) {
    case 1:
    Collections.sort(Personlist1);
    System.out.println(Personlist1.toString());
    break;
    case 2:
    
    int max=0,min=100;int j,k1 = 0,k2=0;
    for(int i=1;i<Personlist1.size();i++)
    {
    j=Personlist1.get(i).getage();
    if(j>max)
    {
    max=j; 
    k1=i;
    }
    if(j<min)
    {
    min=j; 
    k2=i;
    }
    
    } 
    System.out.println("年龄最大:"+Personlist1.get(k1));
    System.out.println("年龄最小:"+Personlist1.get(k2));
    break;
    case 3:
    System.out.println("place?");
    String find = scanner.next(); 
    String place=find.substring(0,3);
    String place2=find.substring(0,3);
    for (int i = 0; i <Personlist1.size(); i++) 
    {
    if(Personlist1.get(i).getbirthplace().substring(1,4).equals(place)) 
    {
    System.out.println("你的同乡:"+Personlist1.get(i));
    }
    }
    
    break;
    case 4:
    System.out.println("年龄:");
    int yourage = scanner.nextInt();
    int close=ageclose(yourage);
    int d_value=yourage-Personlist1.get(close).getage();
    System.out.println(""+Personlist1.get(close));
    
    break;
    case 5:
    isTrue = false;
    System.out.println("再见!");
    break;
    default:
    System.out.println("输入有误");
    }
    }
    }
    public static int ageclose(int age) {
    int m=0;
    int max=53;
    int d_value=0;
    int k=0;
    for (int i = 0; i < Personlist1.size(); i++)
    {
    d_value=Personlist1.get(i).getage()-age;
    if(d_value<0) d_value=-d_value; 
    if (d_value<max) 
    {
    max=d_value;
    k=i;
    }
    
    } return k;
    
    
    }
    
    Search
    
    
    }
    //jiekouwenjiaan
    
    
    public class Person implements Comparable<Person> {
      private String name;
      private String id;
      private int age;
      private String sex;
      private String birthplace;
    
    public String getname() {
    return name;
    }
    public void setname(String name) {
    this.name = name;
    }
    public String getid() {
    return id;
    }
    public void setid(String id) {
    this.id= id;
    }
    public int getage() {
    
    return age;
    }
    public void setage(int age) {
    //int a = Integer.parseInt(age);
    this.age= age;
    }
    public String getsex() {
    return sex;
    }
    public void setsex(String sex) {
    this.sex= sex;
    }
    public String getbirthplace() {
    return birthplace;
    }
    public void setbirthplace(String birthplace) {
    this.birthplace= birthplace;
    }
    
    public int compareTo(Person o) {
    return this.name.compareTo(o.getname());
    
    }
    
    public String toString() {
    return  name+"	"+sex+"	"+age+"	"+id+"	";
    
    Person

    实验结果:

    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 PP;
    
    import java.io.FileNotFoundException;
    import java.io.IOException;
    import java.io.PrintWriter;
    import java.util.Scanner;
    public class Main {
    
        public static void main(String[] args) {
                    Scanner in = new Scanner(System.in);
                    counter min=new counter();
                    PrintWriter out = null;
                    try {
                        out = new PrintWriter("result.txt");
                        int sum = 0;
                        for (int i = 1; i <=10; i++) {
                            int a = (int) Math.round(Math.random() * 100);
                            int b = (int) Math.round(Math.random() * 100);
                            int menu = (int) Math.round(Math.random() * 3);
                            switch (menu) {
                            case 0:
                                System.out.println(i+":"+a + "+" + b + "=");
                                int c1 = in.nextInt();
                                out.println(a + "+" + b + "=" + c1);
                                if (c1 == (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) {
                                    b = (int) Math.round(Math.random() * 100);
                                }
                                System.out.println(i+":"+a + "-" + b + "=");
                                int c2 = in.nextInt();
                                out.println(a + "-" + b + "=" + c2);
                                if (c2 == (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(i+":"+a + "*" + b + "=");
                                int c3 = in.nextInt();
                                out.println(a + "*" + b + "=" + c3);
                                if (c3 == 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){
                                        b = (int) Math.round(Math.random() * 100);
                                    }
                                    while(a % b != 0){
                                        a = (int) Math.round(Math.random() * 100);
                                        
                                    }
                                System.out.println(i+":"+a + "/" + b + "=");
                                int c4 = in.nextInt();
                                if (c4 == 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("你的得分为" + sum);
                        out.println("你的得分为" + sum);
                        out.close();
                    } catch (FileNotFoundException e) {
                        e.printStackTrace();
                    }
                }
            }
    package PP;
    
    
    public class counter<T> {
        private T a;
        private T b;
        public counter() {
            a=null;
            b=null;
        }
        public counter(T a,T b) {
            this.a=a;
            this.b=b;
        }
        public int count1(int a,int b) {
            return a+b;
        }
        public int count2(int a,int b) {
            return a-b;
        }
        public int count3(int a,int b) {
            return a*b;
        }
        public int count4(int a,int b) {
            return a/b;
        }
    }

    实验结果:

    实验总结:

     通过本周的实验我学到了新的知识点集合,知道了集合的作用和它的特点,同时我们也学习了Vectorl类和Stack类,也知道了Java集合框架中的基本接口的实现。总之来说这周收获也是不错的,在做本次实验时还进行了两人一组合作编程。通过合作发现自己的不足和别人的优点,然后加以改正和学习。

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  • 原文地址:https://www.cnblogs.com/D980321/p/9941864.html
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