명품 자바 프로그래밍 5장 실습 문제

✏️ 5장 실습문제 - 1번

package ex;
import java.util.Scanner;

class TV{
    private int size;

    public TV(int size) {
        this.size = size;
    }
    protected int getSize(){
        return size;
    }
}
class ColorTV extends TV{

    private int Color;
    public ColorTV(int size,int Color) {
        super(size);
        this.Color=Color;
    }
    public void printProperty() {
        System.out.println(getSize()+"인치 "+this.Color+"컬러");
    }
}
public class SolveProblem {
    public static void main(String[] args) {
        ColorTV myTV = new ColorTV(32,1024);
        myTV.printProperty();
    }
}

 

✏️ 5장 실습문제 - 2번

package ex;
import java.util.Scanner;

class TV{
    private int size;

    public TV(int size) {
        this.size = size;
    }
    protected int getSize(){
        return size;
    }
}
class IPTV extends TV{

    private int color;
    private String IP;
    public IPTV(String IP, int size, int color){
        super(size);
        this.IP=IP;
        this.color=color;
    }
    public void printProperty() {
        System.out.println("나의 IPTV는 "+this.IP+" 주소의 "+getSize()+"인치 "+this.color+"컬러");
    }
}
public class SolveProblem {
    public static void main(String[] args) {
        IPTV iptv = new IPTV("192.1.1.2",32,2048);
        iptv.printProperty();
    }
}

 

✏️ 5장 실습문제 - 3번

package ex;
import java.util.Scanner;

abstract class Converter{
    abstract protected double convert(double src);
    abstract protected String getSrcString();
    abstract protected String getDestString();
    protected double ratio;

    public void run(){
        Scanner scanner = new Scanner(System.in);
        System.out.println(getSrcString()+"을 "+getDestString()+"로 바꿉니다.");
        System.out.print(getSrcString()+"을 입력하세요>> ");
        double val = scanner.nextDouble();
        double res = convert(val);
        System.out.println("반환 결과: "+res+getDestString()+"입니다");
        scanner.close();
    }

}
class Won2Dollar extends Converter{
    public Won2Dollar(double dollar){
        ratio=dollar;
    }

    @Override
    protected String getSrcString() {
        return "원";
    }

    @Override
    protected double convert(double src) {
        return src/ratio;
    }

    @Override
    protected String getDestString() {
        return "달러";
    }
}
public class SolveProblem {
    public static void main(String[] args) {
        Won2Dollar toDollar = new Won2Dollar(1200);
        toDollar.run();
    }
}

 

✏️ 5장 실습문제 - 4번

package ex;
import java.util.Scanner;

abstract class Converter{
    abstract protected double convert(double src);
    abstract protected String getSrcString();
    abstract protected String getDestString();
    protected double ratio;

    public void run(){
        Scanner scanner = new Scanner(System.in);
        System.out.println(getSrcString()+"을 "+getDestString()+"로 바꿉니다.");
        System.out.print(getSrcString()+"을 입력하세요>> ");
        double val = scanner.nextDouble();
        double res = convert(val);
        System.out.println("반환 결과: "+res+getDestString()+"입니다");
        scanner.close();
    }

}
class km2Mile extends Converter{
    public km2Mile(double a){
        ratio=a;
    }
    @Override
    protected double convert(double src) {
        return src/ratio;
    }

    @Override
    protected String getSrcString() {
        return "km";
    }

    @Override
    protected String getDestString() {
        return "mile";
    }
}
public class SolveProblem {
    public static void main(String[] args) {
        km2Mile toMile = new km2Mile(1.6);
        toMile.run();
    }
}

 

✏️ 5장 실습문제 - 5번

package ex;
import java.util.Scanner;

class Point{
    private int x,y;

    public Point(int x, int y) {
        this.x = x;
        this.y = y;
    }
    public int getX(){
        return x;
    }

    public int getY() {
        return y;
    }
    protected void move(int x, int y){
        this.x=x;
        this.y=y;
    }
}
class ColorPoint extends Point{

    private String color;
    public ColorPoint(int x, int y, String color){
        super(x,y);
        this.color=color;
    }
    public void setXY(int x, int y) {
        move(x,y);
    }

    public void setColor(String color) {
        this.color=color;
    }
    public String toString(){
        String str = this.color+"색의 ("+getX()+","+getY()+")의 점";
        return str;
    }
}
public class SolveProblem {
    public static void main(String[] args) {
         ColorPoint cp =new ColorPoint(5,5,"YELLOW");
         cp.setXY(10,20);
         cp.setColor("RED");
         String str = cp.toString();
         System.out.println(str+"입니다.");
    }
}

 

✏️ 5장 실습문제 - 6번

package ex;
import java.util.Scanner;

class Point {
    private int x, y;

    public Point(int x, int y) {
        this.x = x;
        this.y = y;
    }

    public int getX() {
        return x;
    }

    public int getY() {
        return y;
    }

    protected void move(int x, int y) {
        this.x = x;
        this.y = y;
    }
}

class ColorPoint extends Point {

    private String color;

    public ColorPoint() {
        super(0, 0);
        this.color = "black";
    }
    public ColorPoint(int x, int y){
        super(x,y);
    }

    public void setXY(int x, int y) {
        move(x, y);
    }

    public void setColor(String color) {
        this.color = color;
    }

    public String toString() {
        String str = this.color + "색의 (" + getX() + "," + getY() + ")의 점";
        return str;
    }
}

public class SolveProblem {
    public static void main(String[] args) {
        ColorPoint zeroPoint = new ColorPoint();
        System.out.println(zeroPoint.toString() + "입니다.");

        ColorPoint cp = new ColorPoint(10, 10);
        cp.setXY(5, 5);
        cp.setColor("RED");
        System.out.println(cp.toString() + "입니다.");
    }
}

 

✏️ 5장 실습문제 - 7번

package ex;
import java.util.Scanner;

class Point {
    private int x, y;

    public Point(int x, int y) {
        this.x = x;
        this.y = y;
    }

    public int getX() {
        return x;
    }

    public int getY() {
        return y;
    }

    protected void move(int x, int y) {
        this.x = x;
        this.y = y;
    }
}

class Point3D extends Point {

    private int z;

   public Point3D(int x,int y,int z){
       super(x,y);
       this.z=z;
   }

   public String toString(){
       String str = "("+getX()+","+getY()+","+z+")의 점";
       return str;
   }

    public void moveUp() {
        z++;
    }

    public void moveDown() {
       z--;
    }
    public void move(int x,int y,int z){
       move(x,y);
       this.z=z;
    }
}

public class SolveProblem {
    public static void main(String[] args) {
        Point3D p = new Point3D(1,2,3);
        System.out.println(p.toString()+"입니다.");

        p.moveUp();
        System.out.println(p.toString()+"입니다.");
        p.moveDown();
        p.move(10,10);
        System.out.println(p.toString()+"입니다.");

        p.move(100,200,300);
        System.out.println(p.toString()+"입니다");
    }
}

 

✏️ 5장 실습문제 - 8번

package ex;
import java.util.Scanner;

class Point {
    private int x, y;

    public Point(){
        this.x=0;
        this.y=0;
    }

    public Point(int x, int y) {
        if(x<0||y<0){
            this.x=0;
            this.y=0;
        }
        else {
            this.x = x;
            this.y = y;
        }
    }

    public int getX() {
        return x;
    }

    public int getY() {
        return y;
    }

    protected void move(int x, int y) {
        if(x<0||y<0) {
            this.x = 0;
            this.y = 0;
        }
        else {
            this.x = x;
            this.y = y;
        }
    }
}

class PositiviePoint extends Point {

    public PositiviePoint(){
        super();
    }
    public PositiviePoint(int x, int y) {
        super(x, y);
    }

    public String toString() {
        String str = "(" + getX() + "," + getY() + ")의 점";
        return str;
    }

    @Override
    protected void move(int x, int y) {
        if(x<0||y<0){
            return;
        }
        else
            super.move(x,y);
    }
}

public class SolveProblem {
    public static void main(String[] args) {
        PositiviePoint p = new PositiviePoint();
        p.move(10, 10);
        System.out.println(p.toString() + "입니다.");

        p.move(-5, 5);
        System.out.println(p.toString() + "입니다.");

        PositiviePoint p2 = new PositiviePoint(-10, -10);
        System.out.println(p2.toString() + "입니다.");
    }
}

 

✏️ 5장 실습문제 - 9번

package ex;
import java.util.Scanner;

interface Stack {
    int length();

    int capacity();

    String pop();

    boolean push(String val);
}

class StringStack implements Stack {

    String [] str;
    int size;
    int top;

    public StringStack(int size) {
        this.size=size;
        str = new String[this.size];
        top=this.size;
    }

    @Override
    public int length() {
        return size-top;
    }

    @Override
    public int capacity() {
        return top;
    }

    @Override
    public String pop() {
        int tmp=top;
        top++;
        return str[tmp];
    }

    @Override
    public boolean push(String val) {
        if(top>0){
            str[top-1]=val;
            top--;
            return true;
        }
        else{
            return false;
        }
    }
}

public class SolveProblem {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("총 스택 저장 공간의 크기 입력 >> ");
        int size = scanner.nextInt();
        StringStack stringStack = new StringStack(size);
        while (true) {
            System.out.print("문자열 입력 >> ");
            String str = scanner.next();
            if(str.equals("그만")) {
                int len = stringStack.length();
                if(len==0){
                    System.out.println("현재 스택에 저장된 문자열이 없습니다.");
                }
                else {
                    System.out.print("스택에 저장된 모든 문자열팝 : ");
                    for (int i = 0; i < len; i++)
                        System.out.print(stringStack.pop() + " ");
                    break;
                }
            }
            boolean isCheck = stringStack.push(str);
            if(!isCheck)
                System.out.println("스택이 꽉 차서 푸시 불가!");
        }
    }
}

 

✏️ 5장 실습문제 - 10번

package ex;
import java.util.Scanner;

abstract class PairMap{
    protected String keyArray[];
    protected String valueArray[];
    abstract String get(String key);
    abstract void put(String key, String value);
    abstract String delete(String key);
    abstract int length();
}

class Dictionary extends PairMap{
    private int size;
    private int index=0;
    public Dictionary(int size){
        this.size=size;
        keyArray = new String[this.size];
        valueArray = new String[this.size];
    }

    @Override
    String get(String key) {
        String str="";
        for(int i=0;i< keyArray.length;i++){
            if(key.equals(keyArray[i])){
                str=valueArray[i];
                break;
            }
        }
        return str;
    }

    @Override
    void put(String key, String value) {
        for(int i=0;i< keyArray.length;i++){
            if(key.equals(keyArray[i])){
                valueArray[i]=value;
                return;
            }
        }
        keyArray[index] = key;
        valueArray[index] = value;
        index++;
    }

    @Override
    String delete(String key) {
        String str="";
        for(int i=0;i< keyArray.length;i++){
            if(key.equals(keyArray[i])){
                str=valueArray[i];
                valueArray[i]=null;
                break;
            }
        }
        return str;
    }

    @Override
    int length() {
        return index;
    }
}


public class SolveProblem {
    public static void main(String[] args) {
        Dictionary dic = new Dictionary(10);
        dic.put("황기태","자바");
        dic.put("이재문","파이썬");
        dic.put("이재문","C++");
        System.out.println("이재문의 값은 "+dic.get("이재문"));
        System.out.println("황기태의 값은 "+dic.get("황기태"));
        dic.delete("황기태");
        System.out.println("황기태의 값은 "+dic.get("황기태"));
    }
}

 

✏️ 5장 실습문제 - 11번

package ex;
import java.util.Scanner;

abstract class Calc{
    abstract public void setValue(int a,int b);
    abstract public int calculate(int a,int b);
}
class Add extends Calc {
    int a, b;

    @Override
    public void setValue(int a, int b) {
        this.a = a;
        this.b = b;
    }

    @Override
    public int calculate(int a, int b) {
        return a+b;
    }


}

class Sub extends Calc {
    int a, b;

    @Override
    public void setValue(int a, int b) {
        this.a = a;
        this.b = b;
    }

    @Override
    public int calculate(int a, int b) {
        return a-b;
    }

}

class Mul extends Calc{
    int a, b;

    @Override
    public void setValue(int a, int b) {
        this.a = a;
        this.b = b;
    }

    @Override
    public int calculate(int a, int b) {
        return a*b;
    }
}

class Div extends Calc {
    int a, b;

    @Override
    public void setValue(int a, int b) {
        this.a = a;
        this.b = b;
    }

    @Override
    public int calculate(int a, int b) {
        return a/b;
    }
}




public class SolveProblem {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        Add add = new Add();
        Sub sub = new Sub();
        Mul mul = new Mul();
        Div div = new Div();

        while (true) {
            System.out.print("두 정수와 연산자를 입력하시오(종료: 숫자에 0 입력) >> ");

            int a = sc.nextInt();
            int b = sc.nextInt();
            char c = sc.next().charAt(0);

            if(a==0 && b==0 && c=='0') {
                System.out.println("프로그램을 종료합니다.");
                sc.close();
                break;
            }
            switch (c) {
                case '+' : add.setValue(a, b); System.out.println(add.calculate(a,b)); break;
                case '-' : sub.setValue(a, b); System.out.println(sub.calculate(a,b)); break;
                case '*' : mul.setValue(a, b); System.out.println(mul.calculate(a,b)); break;
                case '/' : div.setValue(a, b); System.out.println(div.calculate(a,b)); break;
                default : System.out.println("연산자를 잘못 입력하셨습니다.");
            }
        }
    }
}

 

✏️ 5장 실습문제 - 12번

 

✏️ 5장 실습문제 - 13번

package ex;
import java.util.Scanner;

interface Shape{
    final double PI = 3.14;
    void draw();
    double getArea();
    default public void redraw(){
        System.out.print(" --- 다시 그립니다.");
        draw();
    }
}

class Circle implements Shape{
    private int r;
    public Circle(int r){
        this.r = r;
    }

    @Override
    public void draw() {
        System.out.println("반지름이 "+this.r+"인 원입니다.");
    }

    @Override
    public double getArea() {
        return r*r*PI;
    }

    @Override
    public void redraw() {
        System.out.print(" --- 다시 그립니다.");
        draw();
    }
}
public class SolveProblem{
    public static void main(String[] args) {
        Shape donut = new Circle(10);
        donut.redraw();
        System.out.println("면적은 "+donut.getArea());
    }
}

 

✏️ 5장 실습문제 - 14번

package ex;
import java.util.Scanner;

interface Shape{
    final double PI = 3.14;
    void draw();
    double getArea();
    default public void redraw(){
        System.out.print(" --- 다시 그립니다.");
        draw();
    }
}

class Circle implements Shape{
    private int r;
    public Circle(int r){
        this.r = r;
    }

    @Override
    public void draw() {
        System.out.println("반지름이 "+this.r+"인 원입니다.");
    }

    @Override
    public double getArea() {
        return r*r*PI;
    }

    @Override
    public void redraw() {
        Shape.super.redraw();
    }
}
class Oval implements Shape{
    private int x,y;
    public Oval(int x,int y){
        this.x=x;
        this.y=y;
    }

    @Override
    public void draw() {
        System.out.println(x+"x"+y+"에 내접하는 타원입니다.");
    }

    @Override
    public double getArea() {
        return x*y*PI;
    }

    @Override
    public void redraw() {
        Shape.super.redraw();
    }
}
class Rect implements Shape{
    private int x,y;
    public Rect(int x,int y){
        this.x=x;
        this.y=y;
    }

    @Override
    public void draw() {
        System.out.println(x+"x"+y+"크기의 사각형 입니다.");
    }

    @Override
    public double getArea() {
        return x*y;
    }

    @Override
    public void redraw() {
        Shape.super.redraw();
    }
}
public class SolveProblem{
    public static void main(String[] args) {
        Shape [] list = new Shape[3];
        list[0]= new Circle(10);
        list[1] = new Oval(20,30);
        list[2] = new Rect(10,40);

        for(int i=0;i< list.length;i++)
            list[i].redraw();
        for(int i=0;i< list.length;i++)
            System.out.println("면적은 "+list[i].getArea());
    }
}