java实验答案

实验一

水仙花数：

class shuixianhua

{//水仙花数

public static void main(String arg[]) {

int i,a,a1,b,b1,c;

for(i=100;i<1000;i++)

{

a=i%10;

a1=i/10;

b=a1%10;

b1=a1/10;

c=b1%10;

if(i==(a*a*a+b*b*b+c*c*c))

System.out.println(i);

}

}

}

输出如下：

153

370

371

407

打印出100以内素数：

public class sushu {

/**

* @param args

*/

public static void main(String[] args) {

// TODO Auto-generated method stub

int i,j,k=0;

for(i=2;i<100;i++){

if(i==2)

System.out.println(i);

i++;

for(j=2;j

{

if(i%j!=0)

k=1;

}

if(k==1)

System.out.println(i);

}

}

求1！+2！+ (20)

public class jiecheng {

public static void main(String[] args) {

int i,sum=0,k;

for(i=1;i<=20;i++)

{

k=ji(i);

sum=k+sum;

}

System.out.print(sum);

}

static int ji(int n)

{

if(n==1)

return 1;

else

return ji(n-1)*n;

}

}

习题2.6

public class Test{

public static void main(String[] args)//第19题,打出图形.菱形{

int n=3;

for(int i=1;i<=n;i++)

{

for(int k=n-1;k>=i;k--)

{

System.out.print(" ");

}

for(int j=1;j<=2*i-1;j++)//打印*

{

System.out.print("*");

}

System.out.println();

}

}

}

编写程序，命令行窗口输出希腊字母表。（希腊字母表开始为α，最后一个为ω）

import java.applet.*;

import java.awt.*;

public class myapplet extends Applet

{

public void paint(Graphics g)

{

String str="";

for(char a='α';a<'ω';a++)

{

str+=a;

}

g.drawString(str, 2, 10);

}

}

实验二

设计一个名为figure的图形软件包（package）。包中包含三角形、矩形、圆三个类。要求：（1）每个类都要构造方法并为成员设置get和set方法；（2）每个类都要有计算周长和面积的成员方法；（3）完成该软件包后的编码后，在另一个包的含有main方法的类中编写代码，分别使用图形软件包中的三个类，生成三个对象，并打印出其周长和面积。

Triangle.java

package figure;

public class Triangle

{

private double a,b,c;

public Triangle(double x,double y,double z)

{

a = x;

b = y;

c = z;

}

public void get()

}

public void set(double x,double y,double z) {

a = x;

b = y;

c = z;

}

public double Perimeter()

{

double per = a + b + c;

return per;

}

public double Area()

{

double area = 0;

double p=(a+b+c)/2;

double s = p*(p-a)*(p-b)*(p-c);

area = (double)Math.sqrt(s);

return area;

}

}

Rectangle.java

package figure;

public class Rectangle

{

private double length;

private double width;

public Rectangle(double l,double w)

{

length = l;

width = w;

}

public void get()

{

}

public void set(double l,double w)

length = l;

width = w;

}

public double Perimeter()

{

double per = 2*(length + width);

return per;

}

public double Area()

{

double area = length * width;

return area;

}

}

Circle.java

package figure;

public class Circle

{

private double r;

private double PI = 3.14;

public Circle(double x)

{

r = x;

}

public double get()

{

return r;

}

public void set(double x)

{

r = x;

}

public double Perimeter()

{

double per = 2*(PI * r);

return per;

}

public double Area()

{

double area = PI*(double)Math.pow(r,2);

return area;

}

}

figureTest.java

package Test;

import figure.Circle;

import figure.Rectangle;

import figure.Triangle;

public class figureTest

{

public static void main(String[] args)

{

Circle c =new Circle(3.2);

System.out.println(c.Area());

System.out.println(c.Perimeter());

Rectangle r = new Rectangle(3,4);

System.out.println(r.Area());

System.out.println(r.Perimeter());

Triangle t = new Triangle(3,4,4);

System.out.println(t.Area());

System.out.println(t.Perimeter());

}

}

编写类Factorial，为其添加两个静态方法（方法名自定义）。其中一个使用递归计算n的阶乘，一个使用非递归计算n的阶乘。构造main方法进行测试。

public class Fac {

public static void main(String[] args) {

int n = 5;

long fac = digui(n);

long fac2 = nonDigui(n);

}

//循环方法

private static long nonDigui(int n) {

long fac = 1L;

for(int i = 1; i<=n ;i++){

fac = fac * i;

}

return fac;

}

//递归

private static long digui(int n) {

if(n == 1){

return 1;

}

return n * digui(n-1);

}

}

按照要求使用Java进行编码。

1)设计一个教师类Teacher，属性有编号（no）、姓名（name）、年龄（age）、所属学

院（seminary），为这些属性设置相应的get和set方法；

2)为Teacher类添加方法equals；（当两个教师对象的no相同时返回true）

3)为Teacher类添加方法toString，通过该方法可以返回“编号为**、姓名为**、年

龄为**的**学院老师”形式的字符串。

4)构造main方法进行测试。

Teacher.java

public class Teacher {

public static int num;

public int no;

public String name;

public int age;

public String seminary;

public Teacher() {

super();

}

public Teacher(int no, String name, int age, String seminary) { super();

this.no = no;

https://www.360docs.net/doc/351952749.html, = name;

this.age = age;

this.seminary = seminary;

}

public static int getNum() {

return num;

}

public static void setNum(int num) {

Teacher.num = num;

}

public int getAge() {

return age;

}

public void setAge(int age) {

this.age = age;

}

public String getName() {

return name;

}

public void setName(String name) {

https://www.360docs.net/doc/351952749.html, = name;

}

public int getNo() {

return no;

}

public void setNo(int no) {

this.no = no;

}

public String getSeminary() {

return seminary;

}

public void setSeminary(String seminary) {

this.seminary = seminary;

}

public boolean equals(Object otherObject){

if (otherObject == null)

return false;

if (getClass() != otherObject.getClass())

return false;

Teacher other = (Teacher) otherObject;

return no == other.no;

}

public String toString(){

return"编号:" + getNo() + "姓名:" + getName() + "年龄:" + getAge()+ "学院老师:"+ getSeminary();

}

}

---------------------------------------

TestTeacher.java

public class TestTeacher {

public static void main(String[] args){

Teacher t1 = new Teacher(1,"zhangsan",43,"计算机");

System.out.println(t1.getNo());

System.out.println(t1.getName());

System.out.println(t1.getAge());

System.out.println(t1.getSeminary());

System.out.println("t1.toString():" + t1);

t1.setName("wangwu");

t1.setAge(50);

t1.setSeminary("国际经贸");

System.out.println(t1.getNo());

System.out.println(t1.getName());

System.out.println(t1.getAge());

System.out.println(t1.getSeminary());

Teacher.setNum(Teacher.getNum() + 1);

System.out.println(Teacher.getNum());

Teacher t2 = new Teacher(2,"lisi",44,"经管");

Teacher.setNum(Teacher.getNum() + 1);

System.out.println(Teacher.getNum());

Teacher t3 = new Teacher(3,"zhouwu",45,"信息");

Teacher.setNum(Teacher.getNum() + 1);

System.out.println(Teacher.getNum());

System.out.println(t2)

}

}

设计一个带表头的单链表（链表中的元素属于同一类型对象，但对象的类型可以随意），提供以下操作：（1）insert：在某个位置插入对象；（2）delete：在某个位置删除对象；（3）delete：删除链表中与x相同的元素；（4）size：返回当前链表中对象的个数；（5）isEmpty：判断链表是否为空；（6）traverse：遍历链表，打印出所有的元素；（7）getData：取得某个位置的对象。构造main函数进行测试。

public class Code {

private int data;

private Code next;

public int getData() {

return data;

}

public void setData(int data) {

this.data = data;

}

public Code getNext() {

return next;

}

public void setNext(Code next) {

this.next = next;

}

}

public class List {

public Code head;

List()

{

this.head=new Code();

head.setData(0);

}

List(int n)

{

this.head=new Code();

Code p,temp;

p=head;

for(int i=0;i

{

temp=new Code();

temp.setData(i+1);

p.setNext(temp);

p=p.getNext();

}

head.setData(n);

}

//判断是否为空

public void IsEmptyList()

{

if (this.head==NULL)

System.out.println("空链表");

else

System.out.println("非空"); }

Public void I

//遍历节点

public void Traverse List()

{

int Size=0;

Code temp;

temp=head;

while(temp.getNext()!=null)

{

Size++;

temp=temp.getNext();

System.out.println(temp.getData());

System.out.println(Size);

}

}

//删除节点

public void DeleteCode(int n)

{

if(n>head.getData()){

System.out.println("找不到第"+n+"个节点"); return;

}

Code temp;

temp=head;

for(int i=0;i

{

temp=temp.getNext();

}

temp.setNext(temp.getNext().getNext()); head.setData(head.getData()-1);

}

//插入节点

public void InsertCode(int n,int d)

{

if(n>head.getData()+1){

System.out.println("找不到第"+n+"个节点"); return;

}

Code p=new Code();

p.setData(d);

Code temp;

temp=head;

for(int i=0;i

{

temp=temp.getNext();

}

p.setNext(temp.getNext());

temp.setNext(p);

}

public static void main(String args[])

{

List l=new List(5);

l.rList();

l.iCode(3,8);

l.rList();

l.dCode(4);

l.rList();

}

}

实验三

1、按照要求使用Java进行编码。

1)编写一个抽象类Shape，其中有抽象方法getArea（）和getPerimeter（）

2)在Shape类的基础上派生出Rectangle和Circle类，二者都实现了计算面积的方法

getArea（）和计算周长的方法getPerimeter（）；

构造main函数，生成Rectangle和Circle对象，并用Shape类型的变量调用Rectangle和Circle对象的getArea（）和getPerim（）方法。

Shape.Java

import java.io.*;

public class Shape {

/**

* @param args

* @author

* @date Dec 4

*/

public static void main(String[] args) throws IOException{

float radius ; // 定义圆的周长

float a,b,c; // 定义三角形的三边长

float w,h; // 定义矩形的宽和长

int select; // 功能选项序号

BufferedReader buf = new BufferedReader(new InputStreamReader(System.in));

String str;

Graphics gp;

while(true)// 控制程序循环

{

PrintMenu();

while(true)

{

str=buf.readLine();

try {

if(str.length()>1 || str.charAt(0)>52 || str.charAt(0)<48)

{

System.out.print("输入不合法！请输入（0-3）的整数: ");

continue;

}

select=Integer.parseInt(str);

while(select > 3 || select <0)

{

System.out.print("输入不合法！请输入（0-3）的整数: ");

continue;

}

break;

}

catch(Exception ne)

{

System.out.print("输入的不是（0-3）之间的整数,请重新输入: ");

continue;

}

}

switch(select)// 处理用户要执行的功能

{

case 1: // 处理圆的情况

System.out.println("请输入圆的半径: ");

while(true)

{

try{

str=buf.readLine();

radius = Float.parseFloat(str);

//Circle circle =new Circle(radius);

if(radius<=0)

{

System.out.print("圆的半径应为大于0的实数,请重新输入圆的半径: ");

continue;

}

System.out.println("圆的半径为：" + radius);

gp = new Circle(radius);

gp.area();

gp.perimeter();

break;// 退出循环

}

catch( NumberFormatException ne)

{

System.out.println("输入的数据不合要求!\n请重新输入圆的半径: ");

continue;

}

}

break;

case 2: // 处理矩形的情况

System.out.println("请输入矩形的长和宽");

while(true)

{

try

{

System.out.print("输入矩形的长: ");

str=buf.readLine();

w=Float.parseFloat(str);

System.out.print("输入矩形的宽: ");

str=buf.readLine();

h=Float.parseFloat(str);

if((w<=0) || (h<=0))

{

System.out.print("输入的数据不符合要求!请重新输入矩形的长和宽: ");

continue;

}

// Rectangle rect=new Rectangle(w,h);

gp = new Rectangle(w,h);

System.out.println("矩形的长和宽为: " + w + "\t" + h);

gp.area();

gp.perimeter();

break; // 退出循环

}

catch(Exception ne)

{

System.out.print("输入的数据不符合要求!请重新输入矩形的长和宽: ");

}

}

break;

case 3:// 处理三角形的情况

while(true)

{

try

{

System.out.println("请输入三角形的三边长");

System.out.print("输入a : ");

str=buf.readLine();

a=Float.parseFloat(str);

System.out.print("输入b : ");

str=buf.readLine();

b=Float.parseFloat(str);

System.out.print("输入c : ");

str=buf.readLine();

c=Float.parseFloat(str);

if(!(a+b>c && a+c>b && b+c>a))// a,b,c不能构成三角形的情况，要求重新输入

{

System.out.print("您输入的三边不能构成三角形!请重新输入三角形的三边长: ");

continue;

}

//输入的三边长可以构成三角形的情况，计算并输出在不久的三角形的面积和周长

// Triangle tri = new Triangle(a,b,c);

System.out.println("三角形的三边长分别为: " + a + "\t" + b + "\t" + c);

gp = new Triangle(a,b,c);

gp.area();

gp.perimeter();

break;// 退出循环

}

catch(Exception ne) //出现异常的处理操作

{

System.out.print("输入的数据不符合要求!请重新输入三角形的三边长: ");

}

}

break;

case 0: //退出

System.out.println("感谢使用!");

System.exit(0);

}//end of switch

}//end of while 程序循环

}// end of main()

public static void PrintMenu() {

System.out.println("\t操作菜单");

System.out.println("1、求圆的面积和周长"); System.out.println("2、求矩形的面积和周长"); System.out.println("3、求三角形的面积和周长"); System.out.println("0、退出");

System.out.print("请选择要执行的操作: ");

}//end of PrintMenu()

}//end of class

Rectangle.java

package exp015S1_2;

public class Rectangle implements Graphics {

/**

* @param args

*/

float weight,height;

public Rectangle(float w,float h)

{

weight=w;

height=h;

}

//求面积

public void area()

{

System.out.println("面积为: "+ weight*height);

}

public void perimeter()

{

System.out.println("周长为: "+ 2*weight*height);

}

}

Circle.java

package exp015S1_2;

public class Circle implements Graphics{

/**

* @param args

*/

float radius; // 定义圆的周长

//Circle类的构造函数

public Circle(float r){

radius = r;

}

//求面积

public void area()

{

System.out.println("面积为: "+ Math.PI*radius*radius);

}

//求周长

public void perimeter()

{

System.out.println("周长为: "+ 2*Math.PI*radius);

}

}

Graphics.java

package exp015S1_2;

/**

* @author Administrator

*

*/

public interface Graphics {

abstract void area(); //求图形面积方法

abstract void perimeter(); //求图形周长方法

}

2、以电话为父类，移动电话和固定电话为两个子类，并使移动电话实现接口：可移动。

固定电话又有子类：无绳电话。定义接口及各类，明确他们的继承关系。

package edu.sdust.sc;

public interface Motive {

}

package edu.sdust.sc;

abstract class Phone{

abstract void call();

}

class MobilePhone extends Phone implements Motive{

public void call(){

}

}

class Telephone extends Phone{

public void call(){

}

}

class NotThreadPhone extends Telephone{

public void call(){

}

}

public class PhoneImpl {

public static void main(String[] args){

}

}

3、在实验2中所实现的Teacher类的基础上，修改Teacher类的代码，要求：由多个Teacher

对象所形成的数组可以使用Arrays.sort方法进行排序（编号由低到高排序）。

public class Teacher{

private int no;

private String name;

private int age;

private String seminary;

public Teacher(int n, String na, int a, String s){

no = n;

name = na;

age = a;

seminary = s;

}

public int getNo(){

return no;

}

public int getAge(){

return age;

}

public String getName(){

return name;

}

public String getSeminary(){

return seminary;

}

Public void setNo(int no){

this.no=no;

}

Public void setName(String name){

https://www.360docs.net/doc/351952749.html,=name;

}

Public void setAge(int age){

this.no=no;

}

Public void setSeminary(String seminary){

this.seminary=seminary;

}

public void set(int no, String name, int age, String seminary){

this.no=no;

https://www.360docs.net/doc/351952749.html,=name;

this.age=age;

this.seminary=seminary;

}

public boolean equals(Object otherObject){

if (otherObject == null)

return false;

if (getClass() != otherObject.getClass())

return false;

Teacher other = (Teacher) otherObject;

return no == other.no;

}

public String toString(){

return"编号:" + getNo() + "姓名:" + getName() + "年龄:" + getAge()+ "学院老师:"+ getSeminary();

}

public static void main(String[] args){

Teacher t1 = new Teacher(101, "Jone", 24, "信息学院");

System.out.println("t2.toString():" + t2);

t1.setNo(102);

t1.setName("Jim");

Teacher t2 = new Teacher(102, "Jone", 23, "信息学院");

System.out.println("t2.toString():" + t2);

Teacher t3 = new Teacher(103, "Tom", 24, "信息学院");

System.out.println("t3.toString():" + t3);