一：理论部分。
一般将数据结构分为两大类：线性数据结构和非线性数据结构
线性数据结构：线性表、栈、队列、串、数组和文件
非线性数据结构：树和图。
线性表：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。
2. 线性表按其存储结构可分为顺序表和链表
3. 用顺序存储结构存储的线性表称为顺序表
4. 顺序表将线性表中的数据元素依次存放在某个存储区域中。一维数组就是用顺序方式存储的线性表。
5. 用链式存储结构存储的线性表称为链表
栈：1. 栈(Stack)也是一种特殊的线性表，是一种后进先出的结构
2. 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(top)，表头称为栈底(bottom)。
3. 栈的物理存储可以用顺序存储结构，也可以用链式存储结构
队列：1. 队列(Queue)是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。
2. 表中允许插入的一端称为队尾，允许删除的一端称为队头
3. 队列的操作是按先进先出的原则进行的。
集合：JAVA的集合框架实现对各种数据结构的封装，以降低对数据管理与处理的难度。
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。
集合类的作用：
1. Java的集合类提供了一些基本数据结构的支持。
2.例如Vector、Hashtable、Stack等。
集合类的特点：1. 只容纳对象
2.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)
Vector类：类似长度可变的数组，只能存放对象，元素通过下标进行访问。
Stack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。）
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。
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); } } |
示例程序1运行结果如下：
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++) {
//if(cats.elementAt(i) instanceof Cat) {
//((Cat) cats.elementAt(i)).print();
//}
((Cat) cats.elementAt(i)).print();//程序有未检查异常
// else {
// ((Dog) cats.elementAt(i)).print();
// }
}
}
}
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++) {
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
}
}
}
}
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]);//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
}
}
示例程序3运行如下：
import java.util.*;
class Counter {
int i = 1;//权限
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));//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);
}
}
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 shiyan;
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));
}
}
}
package shiyan;
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");
}
}
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
{
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);
}
}
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()); } } } |
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 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.");
}
}
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.*;
/**
* An item with a description and a part number.
*/
public class Item implements Comparable<Item>
{
private String description;
private int partNumber;
/**
* Constructs an item.
*
* @param aDescription
* the item's description
* @param aPartNumber
* the item's part number
*/
public Item(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;
Item other = (Item) otherObject;
return Objects.equals(description, other.description) && partNumber == other.partNumber;
}
public int hashCode()
{
return Objects.hash(description, partNumber);
}
public int compareTo(Item other)
{
int diff = Integer.compare(partNumber, other.partNumber);
return diff != 0 ? diff : description.compareTo(other.description);
}
}
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
{
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); } } |
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";//访问指定的关键字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；
l 了解HashMap、TreeMap两个类的用途及常用API。
package map;
/**
* A minimalist employee class for testing purposes.
*/
public class Employee
{
private String name;
private double salary;
/**
* Constructs an employee with $0 salary.
* @param n the employee name
*/
public Employee(String name)
{
this.name = name;
salary = 0;
}
public String toString()
{
return "[name=" + name + ", salary=" + salary + "]";
}
}
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<>();
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));
}
}
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：唐月晨
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；
伙伴的代码及运行结果：
package ID;
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("C:\\Users\\10700\\Documents\\Tencent Files\\1070054343\\FileRecv\\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("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.查找同乡");
System.out.println("4.输出年龄相近的人");
System.out.println("0.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("hometown?");
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 "0":
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 ID;
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+"\t"+sex+"\t"+age+"\t"+number+"\t"+province+"\n";
}
}
package shiyan;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.Random;
import java.util.Scanner;
public class suanshu {
public static void main(String[] args) {
// 用户的答案要从键盘输入，因此需要一个键盘输入流
Scanner in = new Scanner(System.in);
suanshu counter = new suanshu ();
PrintWriter out = null;
try {
out = new PrintWriter("D:\\text.txt");
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
int sum = 0;
// 定义一个变量用来统计得分
// 通过循环生成10道题
for (int i = 0; i < 10; i++) {
// 随机生成两个100以内的随机数作为被除数和除数
int a = (int) Math.round(Math.random() * 100);
int b = (int) Math.round(Math.random() * 100);
int m ;
Random rand = new Random();
m = (int) rand.nextInt(4) + 1;
switch(m) {
case 1:
if (b!=0) {
System.out.println(a + "/" + b + "=");
// 定义一个整数用来接收用户输入的答案
int c = in.nextInt();
// 判断用户输入的答案是否正确，正确给10分，错误不给分
if (c == a / b) {
sum += 10;
System.out.println("true");
}
else {
System.out.println("wrong");
}
}
else {
System.out.println("null");
}
break;
case 2:
System.out.println(a+"+"+b+"=");
int c1=in.nextInt();
if(c1==a+b) {
sum += 10;
System.out.println("true");
}
else {
System.out.println("wrong");
}
break;
case 3:
System.out.println(a+"-"+b+"=");
int c2=in.nextInt();
if(c2==a-b) {
sum += 10;
System.out.println("true");
}
else {
System.out.println("wrong");
}
break;
case 4:
System.out.println(a+"*"+b+"=");
int c3=in.nextInt();
if(c3==a*b) {
sum += 10;
System.out.println("true");
}
else {
System.out.println("wrong");
}
break;
}
//输出用户的成绩
System.out.println("Score"+ ""+ ""+sum);
}
out.println("score:" + sum);
out.close();
}
}
package shiyan;
public class suanshu2<T> {
public class Suanshu<T> {
private T a;
private T b;
public int add(int a,int b) {
return a + b;
}
public int r(int a, int b) {
return a - b;
}
public int m(int a, int b) {
return a * b;
}
public int d(int a, int b) {
if (b != 0 && a%b==0)
return a / b;
else
return 0;
}
}
public int d(int a, int b) {
// TODO 自动生成的方法存根
return 0;
}
public int m(int a, int b) {
// TODO 自动生成的方法存根
return 0;
}
public int add(int a, int b) {
// TODO 自动生成的方法存根
return 0;
}
public int r(int a, int b) {
// TODO 自动生成的方法存根
return 0;
}
}
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 ID;
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("C:\\Users\\10700\\Documents\\Tencent Files\\1070054343\\FileRecv\\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("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.查找同乡");
System.out.println("4.输出年龄相近的人");
System.out.println("0.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("hometown?");
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 "0":
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 ID;
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+"\t"+sex+"\t"+age+"\t"+number+"\t"+province+"\n";
}
}
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。
import java.io.PrintWriter;
import java.util.Random;
import java.util.Scanner;
import java.io.FileNotFoundException;
public class jisuan {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
yunsuan counter = new yunsuan();
PrintWriter out = null;
try {
out = new PrintWriter("test.txt");
} catch (FileNotFoundException e) {
System.out.println("文件夹输出失败");
e.printStackTrace();
}
int sum = 0;
System.out.println("随机生成的四则运算类型");
System.out.println("类型1：除法");
System.out.println("类型2：乘法");
System.out.println("类型3：加法");
System.out.println("类型4：减法");
for (int i = 1; i <= 10; i++) {
int a = (int) Math.round(Math.random() * 100);
int b = (int) Math.round(Math.random() * 100);
int m;
Random rand = new Random();
m = (int) rand.nextInt(4) + 1;
System.out.println("随机生成的四则运算类型：" + m);
switch (m) {
case 1:
a = b + (int) Math.round(Math.random() * 100);
while(b == 0){
b = (int) Math.round(Math.random() * 100);
}
while(a % b != 0){
a = (int) Math.round(Math.random() * 100);
}
//若生成的除法式子必须能整除，且满足分母为0的条件，则a一定要大于b，且a模b的结果要为0。
System.out.println(i + ": " + a + "/" + b + "=");
int c0 = in.nextInt();
out.println(a + "/" + b + "=" + c0);
if (c0 == counter.division(a, b)) {
sum += 10;
System.out.println("right!");
} else {
System.out.println("error!");
}
break;
case 2:
System.out.println(i + ": " + a + "*" + b + "=");
int c = in.nextInt();
out.println(a + "*" + b + "=" + c);
if (c == counter.multiplication(a, b)) {
sum += 10;
System.out.println("right!");
} else {
System.out.println("error!");
}
break;
case 3:
System.out.println(i + ": " + a + "+" + b + "=");
int c1 = in.nextInt();
out.println(a + "+" + b + "=" + c1);
if (c1 == counter.add(a, b)) {
sum += 10;
System.out.println("right!");
} else {
System.out.println("error!");
}
break;
case 4:
while (a < b) {
b = (int) Math.round(Math.random() * 100);
}
//因为不能产生运算结果为负数的减法式子，所以a一定要大于b。若a<b,则重新生成b。
System.out.println(i + ": " + a + "-" + b + "=");
int c2 = in.nextInt();
out.println(a + "-" + b + "=" + c2);
if (c2 == counter.reduce(a, b)) {
sum += 10;
System.out.println("right!");
} else {
System.out.println("error!");
}
break;
}
}
System.out.println("成绩" + sum);
out.println("成绩:" + sum);
out.close();
}
}
public class yunsuan {
private int a;
private int b;
public int add(int a,int b)
{
return a+b;
}
public int reduce(int a,int b)
{
return a-b;
}
public int multiplication(int a,int b)
{
return a*b;
}
public int division(int a,int b)
{
if(b!=0)
return a/b;
else
return 0;
}
}
综上所述：结对编程对编写程序时个人没有关注到的漏洞的问题更容易发现并且解决，会有很多新的想法或是算法设计，减轻了自己编程时的压力同时事半功倍。
实验总结
通过本次实验，我了解了新旧集合类的不同，掌握了Vetor、Stack、Hashtable三个类的用途及常用API，以及集合框架体系组合，和结对伙伴的讨论感受到了编程的快乐，同时也发现了自己的不足，相互交流相互学习有很大的收获。