[JAVA] 명품 자바 프로그래밍 6장 실습문제

1번 문제 코드

import java.util.Scanner;

class MyPoint
{
	int x;
	int y;
	
	MyPoint(int x, int y)
	{
		this.x=x;
		this.y=y;
	}
	
	public String toString()
	{
		return "Point("+x+","+y+")";
	}
	
	boolean equals(MyPoint mp)
	{
		if(this.x==mp.x&&this.y==mp.y)
			return true;
		return false;
	}
	
}

public class Extest{

	public static void main(String[] args) {
		MyPoint p = new MyPoint(3,50);
		MyPoint q = new MyPoint(4,50);
		System.out.println(p);
		if(p.equals(q))
			System.out.println("같은 점");
		else
			System.out.println("다른 점");
	}

}

 

2번 문제 코드

import java.util.Scanner;
class Circle
{
	int x;
	int y;
	int radius;
	
	Circle(int x, int y, int radius)
	{
		this.x=x;
		this.y=y;
		this.radius=radius;
	}
	
	boolean equals(Circle c)
	{
		if(this.x==c.x&&this.y==c.y)
			return true;
		return false;
	}
	
	public String toString()
	{
		return "Circle("+x+","+y+")"+"반지름"+radius;
	}
}

public class Extest{

	public static void main(String[] args) {
		Circle a = new Circle(2,3,5);
		Circle b = new Circle(2,3,30);
		System.out.println("원 a : "+a);
		System.out.println("원 b : "+b);
		if(a.equals(b))
			System.out.println("같은 원");
		else
			System.out.println("서로 다른 원");
	}

}

 

3번 문제 코드

package etc;
public class Calc {
	private int x,y;
	public Calc(int x, int y) { this.x=x; this.y=y; };
	public int sum() { return x+y; }
}

package main;
import etc.Calc;
public class MainApp {
	public static void main(String[] args) {
		Calc c = new Calc(10,20);
		System.out.println(c.sum());
	}
}

 

4번 문제 코드

package base;
public class Shape {
	public void draw() { System.out.println("Shape"); }
}

package derived;
import base.Shape;
public class Circle extends Shape{
	public void draw() { System.out.println("Circle"); }
}

package app;
import derived.Circle;
import base.Shape;
public class GraphicEditor {
	public static void main(String[] args) {
		Shape shape = new Circle();
		shape.draw();
	}
}

 

5, 6번은 생략 (Calendar 클래스 사용)

 

7-1번 문제 코드

import java.util.Scanner;
import java.util.StringTokenizer;
public class Extest{
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		while(true)
		{
			System.out.print(">>");
			String str = scanner.nextLine();
			if(str.equals("그만")) {
				System.out.println("종료합니다...");
				break;
			}
			StringTokenizer st = new StringTokenizer(str," ");
			int count = st.countTokens();
			System.out.println("어절 개수는 "+count);
			
		}
	}

}

 

7-2번 문제 코드

import java.util.Scanner;
public class Extest{
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		while(true)
		{
			System.out.print(">>");
			String str = scanner.nextLine();
			if(str.equals("그만")) {
				System.out.println("종료합니다...");
				break;
			}
			String s[] = str.split(" ");
			System.out.println("어절 개수는 "+s.length);
			
		}
	}

}

 

8번 문제 코드

import java.util.Scanner;
public class Extest{
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		System.out.println("문자열을 입력하세요.");
		String str = scanner.nextLine();
		
		for(int i=1;i<str.length()+1;i++)
		{
			System.out.print(str.substring(i,str.length()));
			System.out.println(str.subSequence(0,i));
		}
	
	}

}

 

9번 문제 코드

class Com{
	
	
	public static void print(int ins ,int com)
	{
		if(ins==1) {
			System.out.print("철수(가위)");

			if(com==1) {
				System.out.println(" : 컴퓨터(가위)");
				System.out.println("비김");
				}
			else if(com==2) {
				System.out.println(" : 컴퓨터(바위)");
				System.out.println("컴퓨터 승");
				}
			else {
				System.out.println(" : 컴퓨터(보)");
				System.out.println("철수 승");
			}
		}
		else if(ins==2) {
			System.out.print("철수(바위)");

			if(com==1) {
				System.out.println(" : 컴퓨터(가위)");
				System.out.println("철수 승");
			}
			else if(com==2) {
				System.out.println(" : 컴퓨터(바위)");
				System.out.println("비김");
				}
			else {
				System.out.println(" : 컴퓨터(보)");
				System.out.println("컴퓨터 승");
				}
		}
		else
		{	
			System.out.print("철수(보)");
			
			if(com==1) {
				System.out.println(" : 컴퓨터(가위)");
				System.out.println("컴퓨터 승");
			}
			else if(com==2) {
				System.out.println(" : 컴퓨터(바위)");
				System.out.println("철수 승");
				}
			else {
				System.out.println(" : 컴퓨터(보)");
				System.out.println("비김");
			}
		}
		
	}
}
public class Extest{
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		while(true) {
		System.out.print("철수[가위(1), 바위(2), 보(3), 끝내기(4)]>>");
		int ins = scanner.nextInt();
		if(ins==4)
			break;
		int com = (int)((Math.random()*3)+1);
		Com.print(ins, com);
		
		
		
		}
	}

}

 

10번 문제 코드

class Person
{
	String name;
	
	
	Person(String name)
	{
		this.name=name;
	}
}

public class Extest{
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		String name;
		System.out.print("1번째 선수의 이름:");
		name=scanner.next();
		Person p1 = new Person(name);
		System.out.print("2번째 선수의 이름:");
		name=scanner.next();
		Person p2 = new Person(name);
		scanner.nextLine();
		
		while(true)
		{
			System.out.print("["+p1.name+"]");
			scanner.nextLine();
			int n1=(int)(Math.random()*3+1);
			int n2=(int)(Math.random()*3+1);
			int n3=(int)(Math.random()*3+1);
			System.out.print(n1+", "+n2+", "+n3+" ");
			if(n1==3&&n2==3&&n3==3)
			{
				System.out.println(p1.name+"님이 이겼습니다!");
				break;
			}
			else
				System.out.println("아쉽습니다.");
			
			System.out.print("["+p2.name+"]");
			scanner.nextLine();
			n1=(int)(Math.random()*3+1);
			n2=(int)(Math.random()*3+1);
			n3=(int)(Math.random()*3+1);
			System.out.print(n1+", "+n2+", "+n3+" ");
			if(n1==3&&n2==3&&n3==3)
			{
				System.out.println(p2.name+"님이 이겼습니다!");
				break;
			}
			else
				System.out.println("아쉽습니다.");
			
		}
		
	}

}

 

11번 문제 코드

public class Extest{
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		
		System.out.print(">>");
		String str = scanner.nextLine();
		StringBuffer sb = new StringBuffer(str);
		
		while(true)
		{
			System.out.print("명령:");
			String cmd = scanner.next();
			if(cmd.equals("그만"))
				break;
			
			String token[] = cmd.split("!");
			if(token.length!=2)
			{
				System.out.println("잘못된 명령입니다.");
				continue;
			}
			
			int index = sb.indexOf(token[0]);
			if(index==-1)
			{
			System.out.println("찾을 수 없습니다.");
			continue;
			}
			
			sb.replace(index, index+token[0].length(),token[1]);
			System.out.println(sb);
			
		}
		
	}
}

 

12번 문제 코드

class Person
{
	String name;
	
	
	Person(String name)
	{
		this.name=name;
	}
}

class Play
{
	Person[] p;
	
	Play(int n)
	{
		p=new Person[n];
	}
}

public class Extest{
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		
		System.out.print("참여자 수:");
		int n=scanner.nextInt();
		Play play = new Play(n);
		
		for(int i=1;i<=n;i++)
		{
			String name;
			System.out.print(i+"번째 선수의 이름:");
			name=scanner.next();
			Person person = new Person(name);
			play.p[i-1]=person;
		}
		scanner.nextLine();
		
		int cnt=0;
		while(true)
		{
			System.out.print("["+play.p[cnt%n].name+"]");
			scanner.nextLine();
			int n1=(int)(Math.random()*3+1);
			int n2=(int)(Math.random()*3+1);
			int n3=(int)(Math.random()*3+1);
			System.out.print(n1+", "+n2+", "+n3+" ");
			if(n1==3&&n2==3&&n3==3)
			{
				System.out.println(play.p[cnt%n].name+"님이 이겼습니다!");
				break;
			}
			else
				System.out.println("아쉽습니다.");
			cnt++;
		}
	}
}