第七章：课上手写编程题

// 计算30的阶乘 
public class Factorial {
    public static void main(String[] args) {
        float fac = 1f;
        for (int i = 1; i <= 30; i++)
            fac *= i;
        System.out.println(fac);
    }
}

// 前20个斐波那契数列 
public class Fibonacci {
    public static void main(String[] args) {
        int[] fib = new int[20];
        fib[0] = 1;
        fib[1] = 1;
        for (int i = 2; i < 20; i++)
            fib[i] = fib[i-1] + fib[i-2];
        for (int i = 0; i < 20; i++)
            System.out.print(fib[i] + "\t");
    } 
}

// 输出数字图形 
public class NumberImage {
    public static void main(String[] args) {
        int n = 1;
        for (int i = 1; i <= 4; i++)
            for (int j = 1; j <= i; j++){
                System.out.print(n++ + "\t");
                if (j == i)
                    System.out.println();
            }    
    } 
}

public class Student{
    public String name;
    public int age;
    public char gender;
    public int sno;
    public String dno;
}

public void displayInfo(){
    System.out.println(name + age + gender + sno +dno);
}

public int sum(int math, int english, int computer){
    return math + english + computer;
}

public Student(){}
public Student(String name, int age, char gender, int sno, String dno){
    this.name = name;
    this.age = age;
    this.gender = gender;
    this.sno = sno;
    this.dno = dno;
}

public class STUDENT {
    public String name;
    public int age;
    public char gender;
    public String classNum;
    public String sno;
    STUDENT(){}
    STUDENT(String name, int age, char gender, String classNum, String sno){
        this.name = name;
        this.age = age;
        this.gender = gender;
        this.classNum = classNum;
        this.sno = sno;
    }
    public void display(){
        System.out.println("姓名：" + this.name + "\t" +
                           "年龄：" + this.age + "\t" +
                           "性别：" + this.gender + "\t" +
                           "所在班级：" + this.classNum + "\t" +
                           "座位号：" + this.sno +"\t");
    }
    public static void main(String[] args) {
        STUDENT s1 = new STUDENT("令狐冲", 23, '男', "01", "01");
        s1.display();
        STUDENT s2 = new STUDENT("任盈盈", 22, '女', "01", "02");
        s2.display();
    }
}

public class RecursionTest {
    public static void main(String[] args) {
        RecursionTest rt = new RecursionTest();
        int i = 5;
        int result = rt.factorial(i);
        System.out.println("运算的结果为：" + result);
    }
    public int factorial(int n){
        if (n < 0) return -1;
        else if (n <= 1) return 1;
        else return factorial(n - 1) * n;
    }
}

import java.util.Scanner;
public class Calculator {
    int count;
    void increment(){
        count++;
        System.out.println(count + "【计数器加1】");
    }
    void decrement(){
        count--;
        System.out.println(count + "【计数器减1】");
    }
    void reset(){
        count = 0;
        System.out.println(count + "【计数器已归零】");
    }
    public static void main(String[] args) {
        Calculator calculator = new Calculator();
        Scanner sin = new Scanner(System.in);
        System.out.print("请输入当前值：");
        calculator.count = sin.nextInt();
        //        归零
        calculator.reset();
        //        加1
        calculator.increment();
        calculator.increment();
        //        减1
        calculator.decrement();
        calculator.decrement();
        //        归零
        calculator.reset();
    }
}

class Mouse{
    public String name;
    public boolean isAlive = true;
    Mouse(String name){
        this.name = name;
    }
    public void display(){
        System.out.println("姓名：" + this.name + "\t状态：" + this.isAlive);
    }
}
class Cat{
    public String name;
    public int record;
    Cat(String name){
        this.name = name;
    }
    public void catchMouse(Mouse m){
        m.isAlive = false;
        this.record++;
    }
    public void display(){
        System.out.println("姓名：" + this.name + "\t抓捕个数：" + this.record);
    }
}
public class Test {
    public static void main(String[] args) {
        Mouse m1 = new Mouse("m1");
        Mouse m2 = new Mouse("m2");
        Mouse m3 = new Mouse("m3");
        Cat c1 = new Cat("c1");
        m1.display();
        m2.display();
        m3.display();
        c1.display();
        System.out.println();
        c1.catchMouse(m1);
        m1.display();
        m2.display();
        m3.display();
        c1.display();
    }
}

public class Employee {
    private String name;
    private int age;
    private double salary;
    Employee(String name, int age, double salary){
        this.name = name;
        this.age = age;
        this.salary = salary;
    }
    Employee(){
        this(null, 0, 0);
    }
    public double setSalsry(){
        return salary;
    }
    public void setSalary(double salary){
        this.salary = salary;
    }
    public double getIncome(){
        return salary;
    }
}

public class Manager {
    private String name;
    private int age;
    private double salary;
    private double bonus;
    Manager(String name, int age, double salary, double bonus){
        this.name = name;
        this.age = age;
        this.salary = salary;
        this.bonus = bonus;
    }
    Manager(){
        this(null, 0, 0, 0);
    }
}

class InvalidDateException extends Exception {
    public InvalidDateException() {
        super();
    }
    public InvalidDateException(String message) {
        super(message);
    }
}
public class MyDate {
    private int year;
    private int month;
    private int day;
    public MyDate(){}
    public MyDate(int year, int month, int day) throws InvalidDateException {
        if (year < 1 || month < 1 || month > 12 || day < 1 || day > 31) {
            throw new InvalidDateException("Invalid date: " + year + "-" + month + "-" + day);
        }
        this.year = year;
        this.month = month;
        this.day = day;
    }
    public void setYear(int year) throws InvalidDateException {
        if (year < 1) {
            throw new InvalidDateException("Invalid year: " + year);
        }
        this.year = year;
    }
    public void setMonth(int month) throws InvalidDateException {
        if (month < 1 || month > 12) {
            throw new InvalidDateException("Invalid month: " + month);
        }
        this.month = month;
    }
    public void setDay(int day) throws InvalidDateException {
        if (day < 1 || day > 31) {
            throw new InvalidDateException("Invalid day: " + day);
        }
        this.day = day;
    }
    public static void main(String[] args) {
        try {
            MyDate d1 = new MyDate(-1, 13, 32);
            MyDate d2 = new MyDate();
            d2.setDay(100);
        } catch (InvalidDateException e) {
            System.out.println("日期输入有误");
        }
    }
}

public class Teacher {
    public String tno;
    public String ins;
    public String sex;
    public int age;
    public Teacher(String tno, String ins, String sex, int age) {
        this.tno = tno;
        this.ins = ins;
        this.sex = sex;
        this.age = age;
    }
    public String getTno() {
        return tno;
    }
    public String getIns() {
        return ins;
    }
    public String getSex() {
        return sex;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String toString(){
        return getTno() + ", " + getIns() + ", " + getSex() + ", " + age;
    }
    public static void main(String[] args) {
        Teacher t = new Teacher("12", "computer", "male", 34);
        t.setAge(35);
        System.out.println(t.toString());
    }
}

public class Animal{
    private String name;
    private int legs;
    public String getName() {
        return name;
    }
    public int getLegs() {
        return legs;
    }
    public Animal(String name, int legs) {
        this.name = name;
        this.legs = legs;
    }
    public Animal(){
        this.name = "ABC";
        this.legs=4;
    }
    public void move(){
        System.out.println(getName() + " Moving!");
    }
    public void move(int n){
        for (int i = 0; i < n; i++){
            System.out.println(getName() + " Moving!");
        }
    }
    public static void main(String[] args) {
        Animal a1 = new Animal("BBB", 2);
        a1.move();
        Animal a2 = new Animal();
        a2.move(3);
    }
}

public class Student {
    private String sNO;
    private String sName;
    private String sSex;
    private int sAge;
    private int sJava;
    public Student(String sNO, String sName, String sSex, int sAge, int sJava) {
        this.sNO = sNO;
        this.sName = sName;
        this.sSex = sSex;
        this.sAge = sAge;
        this.sJava = sJava;
    }
    public String getNO() {
        return sNO;
    }
    public String getName() {
        return sName;
    }
    public String getSex() {
        return sSex;
    }
    public int getAge() {
        return sAge;
    }
    public int getJava() {
        return sJava;
    }
    public void printInfo(){
        System.out.println(getNO() + ", " + getName() + ", " + getSex() + ", " + getAge() + ", " + getAge());
    }
    public static void main(String[] args) {
        Student s1 = new Student("1", "小米", "男", 23, 89);
        Student s2 = new Student("2", "小李", "男", 22, 69);
        s1.printInfo();
        s2.printInfo();
        System.out.println("平均成绩：" + (s1.getJava() + s2.getJava()) / 2);
    }
}

public class Circle {
    private double Radius;
    Circle(){
        this.Radius = 10;
    }
    Circle(double r){
        this.Radius = r;
    }
    public void setRadius(double radius) {
        Radius = radius;
    }
    public double getRadius() {
        return Radius;
    }
    public void show(){
        System.out.println("半径：" + getRadius() + "; " + "面积" + 3.14 * getRadius() * getRadius());
    }
    public static void main(String[] args) {
        Circle c1 = new Circle();
        c1.show();
        Circle c2 = new Circle(20);
        c2.show();
    }
}

package com.exam; import java.awt.*; import java.awt.event.*; import javax.swing.*; public class QQLogin extends JFrame {
    // 定义组件
    JLabel jl1, jl2;
    JTextField jtf1, jtf2;
    JButton jb1, jb2;
    JPanel jp1, jp2, jp3;
    public static void main(String[] args) {
        QQLogin qqLogin = new QQLogin();
    }
    // 构造函数
    public QQLogin() {
        // 创建组件
        jl1 = new JLabel("用户名：");
        jl2 = new JLabel("密    码：");
        jtf1 = new JTextField(15);
        jtf2 = new JTextField(15);
        jb1 = new JButton("确定");
        jb2 = new JButton("重置");
        jp1 = new JPanel();
        jp2 = new JPanel(); 
        jp3 = new JPanel();
        // 设置布局管理器
        this.setLayout(new GridLayout(3, 1));
        // 添加组件
        jp1.add(jl1);
        jp1.add(jtf1);
        jp2.add(jl2);
        jp2.add(jtf2);
        jp3.add(jb1);
        jp3.add(jb2);
        this.add(jp1);
        this.add(jp2);
        this.add(jp3);
        // 设置窗体属性
        this.setTitle("模拟 QQ 登录界面");
        this.setSize(300, 200);
        this.setLocation(400, 200);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setVisible(true);
        // 为“确定”按钮添加事件监听
        jb1.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                // 获取用户名和密码
                String username = jtf1.getText().trim();
                String password = jtf2.getText().trim();
                // 判断用户名和密码是否正确（这里假设用户名和密码都是“123”）
                if (username.equals("123") && password.equals("123")) {
                    JOptionPane.showMessageDialog(null, "用户名和密码输入正确！");
                } else {
                    JOptionPane.showMessageDialog(null, "用户名或密码输入错误！");
                }
            }
        });
        // 为“重置”按钮添加事件监听
        jb2.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                // 清空用户名和密码输入框
                jtf1.setText("");
                jtf2.setText("");
            }
        });
    }
}