명품 자바 프로그래밍(개정4판) 제 7장 실습문제

[1번]

import java.util.Scanner;
import java.util.Vector;

public class p0701 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc=new Scanner(System.in);
		Vector<Integer> v=new Vector<Integer>();
		System.out.print("정수(-1이 입력될 때까지)>> ");
		while(true) {
			int n=sc.nextInt();
			if(n==-1) {
				break;
			}
			v.add(n);
		}
		//최댓값 찾기위해 max를 0번째 수로 설정
		int max=v.get(0);
		for(int i=1;i<v.size();i++) {
			if(max<v.get(i)) {
				max=v.get(i);
			}
		}
		System.out.println("가장 큰 수는 "+max);
	}

}

---

[2번]

import java.util.ArrayList;
import java.util.Scanner;
public class p0702 {
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc=new Scanner(System.in);
		ArrayList<Character> arr=new ArrayList<Character>();
		System.out.print("6개의 학점을 빈 칸으로 분리 입력(A/B/C/D/F)>> ");
		
		for(int i=0;i<6;i++) {
			char c=sc.next().charAt(0);
			arr.add(c);
		}
		
		double sum=0;
		for(int i=0;i<6;i++) {
			switch(arr.get(i)) {
			case 'A':
				sum+=4.0;
				break;
			case 'B':
				sum+=3.0;
				break;
			case 'C':
				sum+=2.0;
				break;
			case 'D':
				sum+=1.0;
				break;
			case 'F':
				sum+=0;
				break;
			}
		}
		System.out.println(sum/6);
	}

}

---

[3번]

import java.util.HashMap;
import java.util.Scanner;
import java.util.StringTokenizer;
public class p0703 {
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc=new Scanner(System.in);
		System.out.println("나라 이름과 인구를 입력하세요.(예: Korea 5000)");
		HashMap<String,String> nations=new HashMap<String,String>();
		while(true) {
			System.out.print("나라 이름, 인구 >>");
			String st=sc.nextLine();
			if(st.equals("그만")) {
				break;
			}
            //토큰나이저를 통해 나라이름과 인구수를 구분지어 해쉬에 put
			StringTokenizer t=new StringTokenizer(st," ");
			String nation=t.nextToken();
			String number=t.nextToken();
			nations.put(nation, number);
		}
		while(true) {
			System.out.print("인구 검색 >> ");
			String st=sc.next();
			if(st.equals("그만")) {
				break;
			}
			if(nations.get(st)==null) {
				System.out.println(st+" 나라는 없습니다.");
			}
			else {
				System.out.println(st+"의 인구는 "+nations.get(st));
			}
		}
	}
}

---

[4번]

import java.util.Scanner;
import java.util.Vector;
public class p0704 {
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc=new Scanner(System.in);
		Vector<Integer> v=new Vector<Integer>();
		
		while(true) {
			System.out.print("강수량 입력 (0 입력시 종료)>> ");
			int n=sc.nextInt();
			if(n==0) {
				break;
			}
			v.add(n);
			int sum=0;
			for(int i=0;i<v.size();i++) {
				int data=v.get(i);
				System.out.print(data+" ");
				sum+=data;
			}
			System.out.println();
			System.out.println("현재 평균 "+sum/v.size());
		}
	}
}

---

[5번]

import java.util.ArrayList;
import java.util.Scanner;
import java.util.StringTokenizer;
class Student{
	private String name,department,studentId,avg;
	
	public Student(String name,String department,String studentId,String avg) {
		this.name=name;
		this.department=department;
		this.studentId=studentId;
		this.avg=avg;
	}
	public String getName() {
		return name;
	}
	public void show() {
		System.out.println("이름:"+name);
		System.out.println("학과:"+department);
		System.out.println("학번:"+studentId);
		System.out.println("학점평균:"+avg);
	}
	public void find() {
		System.out.println(name+","+department+","+studentId+","+avg);
	}
}

public class p0705 {
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc=new Scanner(System.in);
		ArrayList<Student> arr=new ArrayList<Student>();
		System.out.println("학생 이름,학과,학번,학점 평균 입력하세요.");
		for(int i=0;i<4;i++) {
			System.out.print(">> ");
			String st=sc.nextLine();
			StringTokenizer t=new StringTokenizer(st,",");
			//토크나이저후, 앞뒤 공백제거
			String name=t.nextToken().trim();
			String department=t.nextToken().trim();
			String studentId=t.nextToken().trim();
			String avg=t.nextToken().trim();
			arr.add(new Student(name,department,studentId,avg));
		}
		for(int i=0;i<4;i++) {
			System.out.println("--------------------------");
			arr.get(i).show();
		}
		System.out.println("--------------------------");
		
		while(true) {
			System.out.print("학생 이름 >> ");
			String st=sc.next();
			if(st.equals("그만")) {
				break;
			}
			for(int i=0;i<4;i++) {
				if(arr.get(i).getName().equals(st)) {
					arr.get(i).find();
					break;
				}
			}
		}
		sc.close();
	}
}

---

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[6번]

import java.util.HashMap;
import java.util.Iterator;
import java.util.Scanner;
import java.util.Set;
import java.util.StringTokenizer;
class Location{
	private String city;
	private int latitude,longitude;
	
	public Location(String city,int longitude,int latitude) {
		this.latitude=latitude;
		this.longitude=longitude;
		this.city=city;
	}
	public void show() {
		System.out.println(city+"\t"+longitude+"\t"+latitude);
	}
	
}
public class p0706 {
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc=new Scanner(System.in);
		HashMap<String, Location> h=new HashMap<String,Location>();
		System.out.println("도시,경도,위도를 입력하세요.");
		for(int i=0;i<4;i++) {
			System.out.print(">> ");
			String st=sc.nextLine();
			StringTokenizer t=new StringTokenizer(st,",");
			//토크나이저후, 앞뒤 공백제거
			String city=t.nextToken().trim();
			int longitude=Integer.parseInt(t.nextToken().trim());
			int latitude=Integer.parseInt(t.nextToken().trim());
			h.put(city,new Location(city,longitude,latitude));
		}
		Set<String> keys=h.keySet();
		Iterator<String> it=keys.iterator();
		System.out.println("--------------------------");
		while(it.hasNext()) {
			String n=it.next();
			Location l=h.get(n);
			l.show();
		}
		System.out.println("--------------------------");
		
		while(true) {
			System.out.print("도시 이름 >> ");
			String st=sc.next();
			if(st.equals("그만")) {
				break;
			}
			if(h.get(st)!=null) {
				h.get(st).show();
			}
			else {
				System.out.println(st+"는 없습니다.");
			}
		}
		sc.close();
	}
}

---

[7번]

import java.util.HashMap;
import java.util.Iterator;
import java.util.Scanner;
import java.util.Set;
import java.util.StringTokenizer;

public class p0707 {
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc=new Scanner(System.in);
		HashMap<String, Double> h=new HashMap<String,Double>();
		System.out.println("미래장학금관리시스템입니다.");
		
		for(int i=0;i<5;i++) {
			System.out.print("이름과 학점>> ");
			String st=sc.nextLine();
			StringTokenizer t=new StringTokenizer(st," ");
			//토크나이저후, 앞뒤 공백제거
			String name=t.nextToken().trim();
			double score=Double.parseDouble(t.nextToken().trim());
			h.put(name,score);
		}
		
		System.out.print("장학생 선발 학점 기준 입력>> ");
		double flag=sc.nextDouble();
		
		Set<String> keys=h.keySet();
		Iterator<String> it=keys.iterator();
		
		System.out.print("장학생 명단 : ");
		while(it.hasNext()) {
			String name=it.next();
			double score=h.get(name);
			if(flag<=score) {
				System.out.print(name+" ");
			}
		}
		sc.close();
	}
}

---

[8번]

import java.util.HashMap;
import java.util.Iterator;
import java.util.Scanner;
import java.util.Set;
import java.util.StringTokenizer;

public class p0708 {
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc=new Scanner(System.in);
		HashMap<String, Integer> h=new HashMap<String,Integer>();
		System.out.println("** 포인트 관리 프로그램입니다 **");
		
		while(true) {
			System.out.print("이름과 포인트 입력>> ");
			String st=sc.nextLine();
			if(st.equals("그만")) {
				break;
			}
			StringTokenizer t=new StringTokenizer(st," ");
			//토크나이저후, 앞뒤 공백제거
			String name=t.nextToken().trim();
			int point=Integer.parseInt(t.nextToken().trim());
			if(h.get(name)!=null) {
				int temp=h.get(name);
				h.put(name, temp+point);
			}
			else {
				h.put(name,point);
			}
			Set<String> keys=h.keySet();
			Iterator<String> it=keys.iterator();
			while(it.hasNext()) {
				String n=it.next();
				int p=h.get(n);
				System.out.print("("+n+","+p+")");
			}
			System.out.println();
		}
	}		
}

---

[9번]

import java.util.HashMap;
import java.util.Iterator;
import java.util.Scanner;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.Vector;
interface IStack<T>{
	T pop();
	boolean push(T ob);
}

class MyStack<T> implements IStack<T>{
	private Vector<T> v;
	private int size;
	public MyStack (){
		v=new Vector<T>();
		size=-1;
	}
	public T pop() {
		// TODO Auto-generated method stub
		if(size==-1) return null;
		return v.get(size--);
	}

	public boolean push(T ob) {
		v.add(ob);
		size++;
		return true;
	}
	
}

public class p0709 {
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		IStack<Integer> stack=new MyStack<Integer>();
		for(int i=0;i<10;i++) stack.push(i);
		while(true) {
			Integer n=stack.pop();
			if(n==null) break;
			System.out.print(n+" ");
		}
	}		
}

---

[10번]

import java.util.Scanner;
import java.util.Vector;

abstract class Shape{
	public Shape() {
	}
	public abstract void draw();
}

class Line extends Shape{
	public Line() {
		super();
	}
	//오버라이딩
	public void draw() {
		System.out.println("Line");
	}
}

class Rect extends Shape{
	public Rect() {
		super();
	}
	//오버라이딩
	public void draw() {
		System.out.println("Rect");
	}
}

class Circle extends Shape{
	public Circle() {
		super();
	}
	//오버라이딩
	public void draw() {
		System.out.println("Circle");
	}
}

class GraphicEditor{
	private Shape head,tail;
	private Scanner sc;
	Vector<Shape> v;
	//기본생성자
	public GraphicEditor(){
		v=new Vector<Shape>();
		head=null;
		tail=null;
		sc=new Scanner(System.in);
	}
	
	//에디터 실행 메서드
	void runEditor() {
		int choice;
		System.out.println("그래픽 에디터 beauty을 실행합니다.");
		
		do {
		System.out.print("삽입(1), 삭제(2), 모두 보기(3), 종료(4)>>");
		choice=sc.nextInt();
			switch(choice) {
			case 1:
				System.out.print("Line(1), Rect(2), Circle(3)>>");
				int option=sc.nextInt();
				put(option);
				break;
			case 2:
				System.out.print("삭제할 도형의 위치>>");
				int index=sc.nextInt();
				delete(index);
				break;
			case 3:
				print();
				break;
			case 4:
				break;
			default:
				System.out.println("다시 입력해주세요");
				break;
			}
		}while(choice!=4);
		System.out.println("beauty을 종료합니다.");
	}
	
	//리스트에 넣는 메서드
	void put(int num) {
		Shape g;
		//입력번호에 따라 Line,Rect,Circle객체 생성
		switch(num) {
		case 1:
			g=new Line();
			break;
		case 2:
			g=new Rect();
			break;
		case 3:
			g=new Circle();
			break;
		default:
			System.out.println("다시입력해주세요");
			return;
		}
		v.add(g);
		return;
	}
	void delete(int index) {
		if(index>v.size()) {
			System.out.println("삭제할 수 없습니다.");
			return;
		}
		v.remove(index);
	}
	
	void print() {
		for(int i=0;i<v.size();i++) {
			v.get(i).draw();
		}
	}
}

public class p0710 {
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		GraphicEditor ge=new GraphicEditor();
		ge.runEditor();
	}		
}

---

[11-1번]

import java.util.Scanner;
import java.util.Vector;

class quiz{
	private Vector<Nation> v=new Vector<Nation>();
	Scanner sc=new Scanner(System.in);
	public quiz() {
		v.add(new Nation("멕시코","멕시코시티"));
		v.add(new Nation("스페인","리스본"));
		v.add(new Nation("프랑스","파리"));
		v.add(new Nation("영국","런던"));
		v.add(new Nation("그리스","아테네"));
		v.add(new Nation("독일","베를린"));
		v.add(new Nation("일본","동경"));
		v.add(new Nation("중국","베이징"));
		v.add(new Nation("러시아","모스크바"));
	}
	
	public void run() {
		System.out.println("**** 수도 맞추기 게임을 시작합니다. ****");
		while(true) {
			System.out.print("입력:1, 퀴즈:2, 종료:3>> ");
			int op=sc.nextInt();
			if(op==1) {
				input();
			}
			else if(op==2) {
				quizgame();
			}
			else {
				break;
			}
		}
	}
	
	public void input() {
		System.out.println("현재 "+v.size()+"개 나라와 수도가 입력되어 있습니다.");
		while(true) {
			System.out.print("나라와 수도 입력"+(v.size()+1)+">> ");
			String nation=sc.next();
			if(nation.equals("그만")) {
				break;
			}
			String capital=sc.next();
			boolean flag=true;
			for(int i=0;i<v.size();i++) {
				if(v.get(i).getNation().equals(nation)){
					System.out.println(nation+"는 이미 있습니다!");
					flag=false;
					break;
				}
			}
			if(flag) {
				v.add(new Nation(nation,capital));
			}
		}
	}
	public void quizgame() {
		while(true) {
			int index=(int)(Math.random()*v.size());
			
			Nation n=v.get(index);;
			String nation=n.getNation();
			String capital=n.getCapital();
			System.out.print(nation+"의 수도는? ");
			String answer=sc.next();
			
			if(answer.equals("그만")) {
				break;
			}
			
			if(answer.equals(capital)) {
				System.out.println("정답!");
			}
			else {
				System.out.println("아닙니다!");
			}
		}
	}
}

class Nation{
	private String nation,capital;
	public Nation(String nation,String capital) {
		this.nation=nation;
		this.capital=capital;
	}
	public String getNation() {
		return nation;
	}
	public String getCapital() {
		return capital;
	}
}

public class p0711 {
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		quiz q=new quiz();
		q.run();
	}
}

---

[11-2번]

 

import java.util.HashMap;
import java.util.Scanner;
import java.util.Set;
import java.util.Vector;

class quiz{
	private HashMap<String,String>h =new HashMap<String,String>();
	Scanner sc=new Scanner(System.in);
	public quiz() {
		h.put("멕시코","멕시코시티");
		h.put("스페인","리스본");
		h.put("프랑스","파리");
		h.put("영국","런던");
		h.put("그리스","아테네");
		h.put("독일","베를린");
		h.put("일본","동경");
		h.put("중국","베이징");
		h.put("러시아","모스크바");
	}
	
	public void run() {
		System.out.println("**** 수도 맞추기 게임을 시작합니다. ****");
		while(true) {
			System.out.print("입력:1, 퀴즈:2, 종료:3>> ");
			int op=sc.nextInt();
			if(op==1) {
				input();
			}
			else if(op==2) {
				quizgame();
			}
			else {
				break;
			}
		}
	}
	
	public void input() {
		System.out.println("현재 "+h.size()+"개 나라와 수도가 입력되어 있습니다.");
		while(true) {
			System.out.print("나라와 수도 입력"+(h.size()+1)+">> ");
			String nation=sc.next();
			if(nation.equals("그만")) {
				break;
			}
			String capital=sc.next();
			if(h.get(nation)!=null) {
				System.out.println(nation+"은 이미 있습니다!");
			}
			else {
				h.put(nation,capital);
			}
		}
	}
	public void quizgame() {
		while(true) {
			int index=(int)(Math.random()*h.size());
			
			Set<String> keys=h.keySet();
			Object[] arr=keys.toArray();
			
			String nation=(String)arr[index];
			String capital=h.get(nation);
			System.out.print(nation+"의 수도는? ");
			String answer=sc.next();
			
			if(answer.equals("그만")) {
				break;
			}
			
			if(answer.equals(capital)) {
				System.out.println("정답!");
			}
			else {
				System.out.println("아닙니다!");
			}
		}
	}
}


public class p0711 {
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		quiz q=new quiz();
		q.run();
	}
}

---

[12번]

import java.util.HashMap;
import java.util.Scanner;
import java.util.Set;
import java.util.Vector;

class quiz{
	private HashMap<String,String>h =new HashMap<String,String>();
	Scanner sc=new Scanner(System.in);
	public quiz() {
		//h.put으로 초기 17개의 영어단어와 한글 넣기,
	}
	
	public void run() {
		System.out.println("**** 영어 단어 테스트 프로그램 \"명품영여\" 입니다. ****");
		while(true) {
			System.out.print("단어 테스트:1, 단어 삽입:2, 종료:3>> ");
			int op=sc.nextInt();
			if(op==1) {
				quizgame();
			}
			else if(op==2) {
				input();
			}
			else {
				break;
			}
		}
	}
	
	public void input() {
		System.out.println("영어 단어에 그만을 입력하면 입력을 종료합니다.");
		while(true) {
			System.out.print("영어 한글 입력 >> ");
			String eng=sc.next();
			if(eng.equals("그만")) {
				break;
			}			
			String kor=sc.next();
			h.put(eng,kor);
		}
	}
	public void quizgame() {
		while(true) {
			System.out.println("현재 "+h.size()+"개의 단어가 들어 있습니다. -1을 입력하면 테스트를 종료합니다.");
			int index=(int)(Math.random()*h.size());
			
			Set<String> keys=h.keySet();
			Object[] arr=keys.toArray();
			
			String question=(String)arr[index];
			String answer=h.get(question);
			int answeri=(int)(Math.random()*4)+1;
			System.out.println(question+"?");
			for(int i=1;i<=4;i++) {
				if(i==answeri) {
					System.out.print("("+i+")"+h.get((String)arr[index])+" ");
					continue;
				}
				int randomi=(int)(Math.random()*h.size());
				if(randomi==index) {
					i--;
					continue;
				}
				else {
					System.out.print("("+i+")"+h.get((String)arr[randomi])+" ");
				}
			}
			
			int reply=sc.nextInt();
			
			if(reply==-1) {
				break;
			}
			
			if(reply==answeri) {
				System.out.println("Excellent !!");
			}
			else {
				System.out.println("No. !!");
			}
		}
	}
}


public class p0712 {
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		quiz q=new quiz();
		q.run();
	}
}