명품 JAVA Programming 4장 실습문제 정답

 

명품 JAVA Programming 4장 실습문제 정답

 

명품 JAVA Programming 4장 실습문제 정답

 

 

1번

public class MyExp {
    String TV;
    int y;
    int d;

    public MyExp(String TV, int y, int d) {
        this.TV = TV;
        this.y = y;
        this.d = d;
    }

    void show() {
        System.out.println(this.TV + "에서 만든 " + this.y + "년형 " + this.d + "인치 TV");
    }

    public static void main(String[] args) {
        MyExp MyExp = new MyExp("LG", 2017, 32);
        MyExp.show();
    }
}

 

2번

import java.util.Scanner;

public class Grade {
    private int math, science, english;

    public Grade(int math, int science, int english) {
        this.math = math;
        this.science = science;
        this.english = english;
    }

    public int getMath() {
        return math;
    }

    public void setMath(int math) {
        this.math = math;
    }

    public int getScience() {
        return science;
    }

    public void setScience(int science) {
        this.science = science;
    }

    public int getEnglish() {
        return english;
    }

    public void setEnglish(int english) {
        this.english = english;
    }

    public int average() {
        return (math + science + english) / 3;
    }

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

        System.out.print("수학, 과학, 영어 순으로 3개의 점수 입력>>");
        int math = scanner.nextInt();
        int science = scanner.nextInt();
        int english = scanner.nextInt();
        Grade me = new Grade(math, science, english);
        System.out.println("평균은 " + me.average());

        scanner.close();
    }
}

 

그것이 알고싶다, 아줌마가 살해당한 이유

3번

public class Song {
    private String title, artist, country, composer[];
    private int year, track;

    public Song(String title, String artist, int year, String country) {
        this.title = title;
        this.artist = artist;
        this.year = year;
        this.country = country;
    }

    public Song() {
        this(null, null, 0, null);
    }

    public void show() {
        System.out.println("노래 제목 : " + title);
        System.out.println("가수 : " + artist);
        System.out.println("연도 : " + year);
        System.out.println("나라 : " + country);
    }

    public static void main(String[] args) {
        Song song = new Song("Dancing Queen", "ABBA", 1978, "스웨덴국적의");
        song.show();
    }
}

4번

public class Rectangle {
    int x, y, width, height;

    public Rectangle(int x, int y, int width, int height) {
        this.x = x;
        this.y = y;
        this.width = width;
        this.height = height;
    }

    public int square() {
        return this.width * this.height;
    }

    public void show() {
        System.out.printf("(%d,%d) 에서 크기가 %dX%d인 사각형\n", this.x, this.y, this.width, this.height);
    }

    public boolean contains(Rectangle cR) {
        if (cR.x > this.x && cR.y > this.y) {
            if (cR.x + cR.width < this.x + this.width && cR.y + cR.height < this.y + this.height) {
                return true;
            }
        }
        return false;
    }

    public static void main(String[] args) {
        Rectangle r = new Rectangle(2, 2, 8, 7);
        Rectangle s = new Rectangle(5, 5, 6, 6);
        Rectangle t = new Rectangle(1, 1, 10, 10);

        r.show();
        System.out.println("s의 면적은" + s.square());
        if (t.contains(r)) System.out.println("t는 r을 포함합니다.");
        if (t.contains(s)) System.out.println("t는 s를 포함합니다.");
    }
}

 

팔도 왕뚜껑 매출 절반이 날아갔던 사건

5번

this.x = x; this.y = y; this.radius = radius;
System.out.println("(" + x + "," + y + ")" + radius);
new Scanner(System.in);
new Circle[3];
c.length
double x = scanner.nextDouble();
double y = scanner.nextDouble();
int radius = scanner.nextInt();
new Circle(x, y, radius);
c[i].show.close();

6번

import java.util.Scanner;

public class Circle {
    private double x, y;
    private int radius;

    public Circle(double x, double y, int radius) {
        this.x = x;
        this.y = y;
        this.radius = radius;
    }

    public double area() {
        return radius * radius * 3.14;
    }

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

        Circle c[] = new Circle[3];
        double max;
        int j = 0;
        for (int i = 0; i < c.length; i++) {
            System.out.print("x, y, radius==>");
            Double x = s.nextDouble();
            Double y = s.nextDouble();
            int radius = s.nextInt();

            c[i] = new Circle(x, y, radius);
        }
        max = c[0].area();

        for (int i = 0; i < c.length; i++) {
            if (max < c[i].area()) {
                max = c[i].area();
                j = i;
            }
        }
        System.out.println("가장 큰 면적인 큰 원은" + "(" + c[j].x + "," + c[j].y + ")" + c[j].radius);
    }
} 

7번

public class Day {
    private String work;

    public Day(String work) {
        this.work = work;
    }

    public void set(String work) {
        this.work = work;
    }

    public String get() {
        return work;
    }

    public void show() {
        if (work == null) System.out.println("없습니다.");
        else System.out.println(work + "입니다.");

        System.out.println();
    }
}
import java.util.Scanner;

public class MonthSchedule {
    private int x;
    Day[] day = null;

    Scanner sc = new Scanner(System.in);

    public MonthSchedule(int x) {
        this.x = x;
        day = new Day[x];
    }

    public void input() {
        System.out.print("날짜(1~30)?");
        int i = sc.nextInt();

        System.out.print("할일(빈칸없이입력)?");
        String work = sc.next();
        day[i] = new Day(work);

        System.out.println();
    }

    public void view() {
        System.out.print("날짜(1~30)?");
        int date = sc.nextInt();

        System.out.print(date + "일의 " + "할 일은 " + day[date]);
    }

    public void finish() {
        System.out.println("프로그램을 종료합니다.");
    }

    public void run() {
        while (true) {
            System.out.print("할일(입력:1, 보기:2, 끝내기:3)" + " >>");
            int sel = sc.nextInt();

            if (sel == 1) {
                input();
            } else if (sel == 2) {
                view();
            } else if (sel == 3) {
                finish();
                break;
            } else {
                System.out.println("1, 2, 3중에 입력하세요.");
            }
        }
    }

    public static void main(String[] args) {
        MonthSchedule april = new MonthSchedule(30);

        System.out.println("이번달 스케쥴 관리 프로그램.");

        april.run();
    }
}

8번

 

 

 

9번

 

 

10번

 

 

11번

import java.util.Scanner;

class Add {
    int a, b;

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

    int calculate() {
        return a + b;
    }
}

class Sub {
    int a, b;

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

    int calculate() {
        return a - b;
    }
}

class Mul {
    int a, b;

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

    int calculate() {
        return a * b;
    }
}

class Div {
    int a, b;

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

    double calculate() {
        return (double) a / b;
    }
}

public class Cal {

    public static void main(String[] args) {
        System.out.print("두 정수와 연산자를 입력하시오>>");
        Scanner sd = new Scanner(System.in);
        int x = sd.nextInt();
        int y = sd.nextInt();
        char ch = sd.next().charAt(0);

        switch (ch) {
            case '+':
                Add a = new Add();
                a.setValue(x, y);
                System.out.println(a.calculate());
                break;
            case '-':
                Sub s = new Sub();
                s.setValue(x, y);
                System.out.println(s.calculate());
                break;
            case '*':
                Mul m = new Mul();
                m.setValue(x, y);
                System.out.println(m.calculate());
                break;
            case '/':
                Div d = new Div();
                d.setValue(x, y);
                System.out.println(d.calculate());
                break;
        }
    }
}

 

지금 서울 땅 팔면 일본 전체의 80%를 살 수 있다

12번

import java.util.Scanner;

class Reservesystem {
    String[] sname;
    String[] aname;
    String[] bname;
    int seat;

    Reservesystem() {
        sname = new String[10];
        aname = new String[10];
        bname = new String[10];
        for (int i = 0; i < sname.length; i++) {
            sname[i] = "---";
            aname[i] = "---";
            bname[i] = "---";
        }
    }

    void printSname() {
        System.out.print("S>>");
        for (int i = 0; i < sname.length; i++) {
            System.out.print(" " + sname[i]);
        }
        System.out.println();
    }

    void printAname() {
        System.out.print("A>>");
        for (int i = 0; i < aname.length; i++) {
            System.out.print(" " + aname[i]);
        }
        System.out.println();
    }

    void printBname() {
        System.out.print("B>>");
        for (int i = 0; i < bname.length; i++) {
            System.out.print(" " + bname[i]);
        }
        System.out.println();
    }

    void inquiry() {
        printSname();
        printAname();
        printBname();
        System.out.println("<<<조회를 완료하였습니다.>>>");
    }

    void seatchoice() {
        System.out.print("좌석 구분 S(1), A(2), B(3) >> ");
        Scanner s = new Scanner(System.in);
        seat = s.nextInt();
    }

    void setSeat(String name, int num) {
        switch (seat) {
            case 1:
                if (sname[num - 1] == "---") // 중복 검
                    sname[num - 1] = name;
                else
                    System.out.println("이미 예약된 자리");
                break;
            case 2:
                if (aname[num - 1] == "---")
                    aname[num - 1] = name;
                else
                    System.out.println("이미 예약된 자리");
                break;
            case 3:
                if (bname[num - 1] == "---")
                    bname[num - 1] = name;
                else
                    System.out.println("이미 예약된 자리");
                break;
            default:
                System.out.println("없는 메뉴");
                break;
        }
    }

    void printAllseat() {
        switch (seat) {
            case 1:
                printSname();
                break;
            case 2:
                printAname();
                break;
            case 3:
                printBname();
                break;
            default:
                System.out.println("없는 메뉴");
                break;
        }
    }

    void reservation() {
        seatchoice();
        String name;
        int num;
        printAllseat();

        System.out.print("이름 : ");
        Scanner s = new Scanner(System.in);
        name = s.next();
        System.out.print("번호 : ");
        num = s.nextInt();
        if (num > 0 && num < 11)
            setSeat(name, num);
        else
            System.out.println("없는 번호");
    }

    void cancel() {
        seatchoice();
        printAllseat();
        String name;
        int i = 0;
        System.out.print("이름 : ");
        Scanner s = new Scanner(System.in);
        name = s.next();
        switch (seat) {
            case 1:
                for (; i < sname.length; i++) {
                    if (sname[i].equals(name)) {
                        sname[i] = "---";
                        break;
                    }
                }
                break;
            case 2:
                for (; i < aname.length; i++) {
                    if (aname[i].equals(name)) {
                        aname[i] = "---";
                        break;
                    }
                }
                break;
            case 3:
                for (; i < bname.length; i++) {
                    if (bname[i].equals(name)) {
                        bname[i] = "---";
                        break;
                    }
                }
                break;
            default:
                System.out.println("없는 메뉴");
                break;
        }
        if (i == 10) {
            System.out.println("없는 이름");
        }
    }
}
import java.util.Scanner;

public class Concert {

    public static void main(String[] args) {
        Reservesystem r = new Reservesystem();
        while (true) {
            System.out.print("예약(1), 조회(2), 취소(3), 끝내기(4) >> ");
            Scanner sd = new Scanner(System.in);

            int ch = sd.nextInt();
            switch (ch) {
                case 1:
                    r.reservation();
                    break;
                case 2:
                    r.inquiry();
                    break;
                case 3:
                    r.cancel();
                case 4:
                    break;
                default:
                    System.out.println("없는 메뉴");
                    break;
            }
            if (ch == 4) {
                break;
            }
        }
    }
}