编程题部分

Posted 2021-05-26 3cH0-Nu1L

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Circle类：

输入：

4
5

-4
-2

输出：

this is a constructor
Circle [radius=2]
c1:area=12
this is a constructor
Circle [radius=2]
Circle [radius=4]
c2:area=50
this is a constructor with para
Circle [radius=5]
c3:area=78

this is a constructor
Circle [radius=2]
c1:area=12
this is a constructor
Circle [radius=2]
Circle [radius=2]
c2:area=12
this is a constructor with para
Circle [radius=2]
c3:area=12

代码：

import java.util.Scanner;
import java.lang.Math.*;

public class Main {
    public static class Circle {
        private int radius;
        Circle() {
            this.radius = 2;
            System.out.println("this is a constructor");
        }
        Circle(int radius) {
            this.radius = radius;
            if (this.radius <= 0) {
                this.radius = 2;
//                System.out.println("this is a constructor with para");
            }
            System.out.println("this is a constructor with para");

        }
        public void setter(int r){
            this.radius = r;
            if(r <= 0){
                this.radius = 2;
            }
        }
        public int getter(){
            return this.radius;
        }
        public int gerArea(){
            double s;
            s = Math.PI * radius * radius;
            return (int)s;
        }
        public String toString(){
            String str = "Circle [radius=" + this.radius + "]";
            return str;
        }
    }
    public static void main(String[]args){
//        c1:
        Circle c1 = new Circle();
        String str1 = c1.toString();
        System.out.println(str1);
        int s1 = c1.gerArea();
        System.out.println("c1:area=" + s1);
//        c2:
        Circle c2 = new Circle();
        String str2 = c2.toString();
        System.out.println(str2);
        Scanner in = new Scanner(System.in);
        int r = in.nextInt();
        c2.setter(r);
        String str22 = c2.toString();
        System.out.println(str22);
        int s2 = c2.gerArea();
        System.out.println("c2:area=" + s2);
//        c3:
        int rr = in.nextInt();
        Circle c3 = new Circle(rr);
        String str3 = c3.toString();
        System.out.println(str3);
        int s3 = c3.gerArea();
        System.out.println("c3:area=" + s3);
    }
}

View Code

设计一个风扇Fan类：

设计一个名为Fan的类表示一个风扇。这个类包括：

1.三个名为SlOW、MEDIUM和FAST，其值为1、2和3常量表示风扇的速度。

2.一个名为speed的int类型私有数据域表示风扇的速度（默认值为SLOW）。

3.一个名为on的boolean类型私有数据域表示风扇是否打开（默认值为false）。

4.一个名为radius的double类型私有数据域表示风扇的半径（默认值为5）。

5.一个名为color的string类型数据域表示风扇的颜色（默认值为white）。

6.这四个成员变量(数据域)的访问器和修改器。

7.一个无参构造方法;

8.一个有参构造方法 public Fan(int fanSpeed,boolean fanOn,double fanRadius,String fanColor) { ... }，

9.一个名为toString()的方法返回描述风扇的字符串。如果风扇是打开的，那么该方法在一个组合的字符串中返回风扇的速度、颜色和半径。如果风扇没有打开，该方法就会返回一个由"fan is off"和风扇颜色以及半径组合成的字符串。

请在自己的草稿本上画出UML图，养成良好的设计习惯。

要求：创建两个Fan对象：

第一个对象利用无参构造方法构造默认风扇对象Fan1；

第二个对象依据输入的风扇属性，调用有参构造方法构造自定义风扇对象Fan2。

通过调用它们的toString方法显示这些对象。

输入：

2
True
6
Red

输出：

-------
Default
-------
speed 1
color white
radius 5.0
fan is off
-------
My Fan
-------
speed 2
color Red
radius 6.0
fan is on

代码：

import java.util.*;

public class Main {
    public static void main(String[]args){
        Fan f1 = new Fan();
        String s1 = f1.toString();
        System.out.println(s1);
        Scanner in = new Scanner(System.in);
        int speed = in.nextInt();
        boolean on = in.hasNextBoolean();
        double radius = in.nextDouble();
        String color = in.next();

        Fan f2 = new Fan();
        f2.setspeed(speed);
        f2.setColor(color);
        f2.seton(on);
        f2.setradius(radius);
        String s2 = f2.toString();
        System.out.println(s2);
    }
    public static class Fan{
        static  int SLOW=1, MEDIUM=2, FAST=3;
        private int speed = 1;
        private boolean on = false;
        private double radius = 5;
        String color = "white";
        Fan(){
        }
        public Fan(int fanSpeed, boolean fanOn, double fanRadius, String fanColor){
            speed = fanSpeed;
            on = fanOn;
            radius = fanRadius;
            color = fanColor;
        }
        public void setspeed(int fanspeed){
            this.speed = fanspeed;
        }
        public void setColor(String fancolor){
            this.color = fancolor;
        }
        public void setradius(double fanradius){
            this.radius = fanradius;
        }
        public void seton(boolean fanon){
            this.on = fanon;
        }
        public String toString(){
            String s1, s2, s3, s4, s5;
            if(this.on == false){
                s1 = "-------\\nDefaut\\n-------\\n";
                s2 = "speed 1\\n";
                s3 = "color white\\n";
                s4 = "radius 5.0\\n";
                s5 = "fan is off\\n";
            }
            else{
                s1 = "-------\\nMy Fan\\n-------";
                s2 = "speed " + this.speed + "\\n";
                s3 = "color " + this.color + "\\n";
                s4 = "radius " + this.radius + "\\n";
                s5 = "fan is on\\n";
            }
            return s1 + s2 + s3 + s4 + s5;
        }
    }
}

View Code

设计一个BankAccount类：

输入：

700
70
7

输出：

700
630
637

代码：

import java.util.Scanner;

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

        Scanner in = new Scanner(System.in);
        int a1 = in.nextInt();
        int a2 = in.nextInt();
        int a3 = in.nextInt();
        BankAccount b = new BankAccount(a1);
        int a = b.getBlance();
        System.out.println(a);
        b.withdraw(a2);
        b.deposit(a3);
    }
    public static class BankAccount{
        public int balance;
        BankAccount(){
            this.balance = 0;
        }
        BankAccount(int balance){
            this.balance = balance;
        }
        public int getBlance(){
            return this.balance;
        }
        public void withdraw(int amount){
            this.balance = this.balance - amount;
            System.out.println(this.balance);
        }
        public void deposit(int a){
            this.balance += a;
            System.out.println(this.balance);
        }

    }
}

View Code

学生类设计：

输入：

tom 6

jerry 8

输出：

无参构造方法
name:无名,age:7
name:tom,age:7

无参构造方法
name:无名,age:7
name:jerry,age:8

代码：

import java.util.Scanner;

public class Main {
    public static void main(String[]args){
        Student s1 = new Student();
        Scanner in = new Scanner(System.in);
        String name = in.next();
        int age = in.nextInt();
        s1.setname(name);
        s1.setage(age);
        s1.display();
    }
    public static class Student{
        private String name;
        private int age;
        public void setname(String name){
            this.name = name;
        }
        public void setage(int age){
            this.age = age;
            if(age <= 6)
                this.age = 7;
        }
        public String getname(){
            return this.name;
        }
        public int getage(){
            return this.age;
        }
        Student(){
            System.out.println("无参构造方法");
            this.name = "无名";
            this.age = 7;
            System.out.println("name:无名,age:7");
        }
        Student(String name, int age){
            this.name = name;
            this.age = age;
        }
        public void display(){
            System.out.println("name:" + this.name + ",age:" + this.age);
        }
    }
}

View Code

定义类与创建对象：

输入：

输出：

this person is lili,her age is 19
this person is lucy,her age is 20

代码：

public class Main {
    public static void main(String[]args){
        Person p1 = new Person("lili", 19);
        Person p2 = new Person("lucy", 20);

    }
    public static class Person{
        public String name;
        public int age;
        Person(String name, int age){
            this.name = name;
            this.age = age;
            System.out.println("this person is " + this.name + ",her age is " + this.age);
        }
    }
}

View Code

继承覆盖综合练习-Person、Student、Employee、Company：

输入：

s zhang 23 false 001 net15
e wang 18 true 3000.51 IBM
s zhang 23 false 001 net15
e bo 25 true 5000.51 IBM
e bo 25 true 5000.52 IBM
e bo 18 true 5000.54 IBM
e tan 25 true 5000.56 IBM
e tan 25 true 5000.51 IBM
s wang 17 false 002 null
s wang 17 false 002 null
e hua 16 false 1000 null
s wang 17 false 002 net16
e hua 16 false 1000 null
e hua 18 false 1234 MicroSoft
!
continue

输出：

Employee:bo-18-true-IBM-5000.54
Employee:bo-25-true-IBM-5000.51
Employee:bo-25-true-IBM-5000.52
Employee:hua-16-false-null-1000.0
Employee:hua-16-false-null-1000.0
Employee:hua-18-false-MicroSoft-1234.0
Employee:tan-25-true-IBM-5000.56
Employee:tan-25-true-IBM-5000.51
Student:wang-17-false-002-null
Student:wang-17-false-002-null
Student:wang-17-false-002-net16
Employee:wang-18-true-IBM-3000.51
Student:zhang-23-false-001-net15
Student:zhang-23-false-001-net15
stuList
Student:wang-17-false-002-null
Student:wang-17-false-002-net16
Student:zhang-23-false-001-net15
empList
Employee:bo-18-true-IBM-5000.54
Employee:bo-25-true-IBM-5000.51
Employee:hua-16-false-null-1000.0
Employee:hua-18-false-MicroSoft-1234.0
Employee:tan-25-true-IBM-5000.56
Employee:tan-25-true-IBM-5000.51
Employee:wang-18-true-IBM-3000.51

代码：

import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner se = new Scanner(System.in);
        ArrayList <Person> 列表=new ArrayList <Person>();
        while (true) {
            String s或e =se.next();
            if(s或e.equals("s")) {
                列表.add(new Student(se.next(),se.nextInt(),se.nextBoolean(),se.next(),se.next()));
            }else if(s或e.equals("e")) {
                列表.add(new Employee(se.next(),se.nextInt(),se.nextBoolean(),se.nextDouble(),new Company(se.next())));
            }else {
                break;
            }
        }
        Collections.sort(列表, new 排序类());
        for(Person 一个人:列表) {
            if(一个人 instanceof Student) {
                System.out.println(((Student)一个人).toString());
            }else {
                System.out.println(((Employee)一个人).toString());
            }
        }
        String 输入exit或其他=se.next();
        if(输入exit或其他.equals("exit")) {
            return;
        }else {
            ArrayList <Student> stuList=new ArrayList <Student>();
            ArrayList <Employee> empList=new ArrayList <Employee>();
            for(Person w:列表) {
                if(w instanceof Student) {
                    if(!stuList.contains((Student)w)) {
                        stuList.add((Student)w);
                    }
                }
                if(w instanceof Employee) {
                    if(!empList.contains((Employee)w)) {
                        empList.add((Employee)w);
                    }
                }
            }
            System.out.println("stuList");
            for(Student a:stuList) {
                System.out.println(a.toString());
            }
            System.out.println("empList");
            for(Employee a:empList) {
                System.out.println(a.toString());
            }
        }
    }
}
abstract class Person{
    String name;int age; boolean gender;
    public Person(String name, int age, boolean gender) {
        super();
        if(name.equals("null")) {
            this.name = null;
        }else {
            this.name = name;
        }
        this.age = age;
        this.gender = gender;
    }

    @Override
    public String toString() {
        return name + "-" + age + "-" + gender;
    }
    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Person other = (Person) obj;
        if (age != other.age)
            return false;
        if (gender != other.gender)
            return false;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        return true;
    }
    
}
class Student extends Person{
    String stuNo,clazz;
    public Student(String name, int age, boolean gender, String stuNo, String clazz) {
        super(name, age, gender);
        if(stuNo.equals("null")) {
            this.stuNo = null;
        }else {
            this.stuNo = stuNo;
        }
        if(clazz.equals("null")) {
            this.clazz = null;
        }else {
            this.clazz = clazz;
        }
    }
    @Override
    public String toString() {
        return "Student:" + super.toString()+"-"+ stuNo + "-" + clazz;
    }
    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (!super.equals(obj))
            return false;
        if (getClass() != obj.getClass())
            return false;
        Student other = (Student) obj;
        if (clazz == null) {
            if (other.clazz != null)
                return false;
        } else if (!clazz.equals(other.clazz))
            return false;
        if (stuNo == null) {
            if (other.stuNo != null)
                return false;
        } else if (!stuNo.equals(other.stuNo))
            return false;
        return true;
    }
    
}
class Company{
    String name;

    public Company(String name) {
        if(!name.equals("null")) {
            this.name = name;
        }else {
            this.name = null;
        }
    }

    @Override
    public String toString() {
        return name;
    }
    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Company other = (Company) obj;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        return true;
    }
}
class Employee extends Person{
    Company company; 
    double salary;
    public Employee(String name, int age, boolean gender, double salary, Company company) {
        super(name, age, gender);
        this.company = company;
        this.salary = salary;
    }
    @Override
    public String toString() {
        return "Employee:" +super.toString()+"-"+ company + "-" + salary ;
    }
    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (!super.equals(obj))
            return false;
        if (getClass() != obj.getClass())
            return false;
        Employee other = (Employee) obj;
        String newpersalary = new DecimalFormat("#.#").format(other.salary);
        String newthissalary = new DecimalFormat("#.#").format(this.salary);
        if (company == null) {
            if (other.company != null)
                return false;
        } else if (!company.equals(other.company))
            return false;
        if (!newpersalary.equals(newthissalary))
            return false;
        return true;
    }
}
class 排序类 implements Comparator<Person>{
    @Override
    public int compare(Person o1, Person o2) {
        if(o1.name.compareTo(o2.name)>0) {
            return 1;
        }else if(o1.name.compareTo(o2.name)<0) {
            return -1;
        }else {
            if(o1.age>o2.age) {
                return 1;
            }else if(o1.age<o2.age) {
                return -1;
            }else {
                return 0;
            }
        }
    }
}

View Code

设计一个Shape及其子类Oval：

输入：

8 6

输出：

The area of Oval(a:8.0,b:6.0) is 150.79644480000002
The perimeterof Oval(a:8.0,b:6.0) is 44.42882862370954

代码：

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        double a = in.nextDouble();
        double b = in.nextDouble();
        Oval oval = new Oval(a, b);
        System.out.println("The area of " + oval.toString() + " is " + oval.area());
        System.out.println("The perimeterof " + oval.toString() + " is " + oval.perimeter());
    }
}
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