[자바] 멀티미디어자바프로젝트II ch.07 연습문제

package _1027_A;
import java.util.*;
// 키보드로 문자열을 4개 입력 받아 ArrayList에 삽입하고 가장 긴 이름을 출력하라.
// 가장 긴 이름은 : Ashley
public class Main {
    public static void main(String[] args) {
        ArrayList<String> s = new ArrayList<String>();
        int index = 0, max = -1;
        for(int i = 0; i < 4; i++) {
            Scanner sc = new Scanner(System.in);
            System.out.print("이름을 입력하세요>>");
            s.add(new String(sc.nextLine()));
            
            if(max < s.get(i).length()) {
                max = s.get(i).length();
                index = i;
            }
        }
        for (String str : s) {
            System.out.print(str+" "); 
        }
        System.out.println("\n"+s.get(index)); 
    }
}
 

 

package _1027_B;
 
import java.util.HashSet;
import java.util.Iterator;
 
public class Main {
 
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        HashSet<Person> hSet = new HashSet<Person>();
        hSet.add(new Person("Lee", 24));
        hSet.add(new Person("Hong", 29));
        hSet.add(new Person("Choi", 21));
        hSet.add(new Person("Hong", 28));
        printCollection(hSet.iterator());
 
        System.out.println();
 
        deleteCollectionByHash(hSet, "Hong");
        printCollection(hSet.iterator());
    }
 
    public static void printCollection(Iterator<Person> itr) {
        while (itr.hasNext())
            itr.next().ShowData();
    }
 
    /**
     * 해쉬 값을 이용하여 해당 오브젝트를 제거 O(1)
     */
    public static void deleteCollectionByHash(HashSet<Person> hSet, String name) {
        hSet.remove(new Person(name));
    }
 
    /**
     * 평범한 방식인 순차탐색을 이용하여 해당 오브젝트를 제거 O(n)
     */
    public static void deleteCollectionBySearch(HashSet<Person> hSet, String name) {
        Iterator<Person> itr = hSet.iterator();
 
        while (itr.hasNext()) {
            if (itr.next().GetName().equals(name)) {
                itr.remove();
            }
        }
    }
}
 

package _1027_B;
 
public class Person {
    private String mName;
    private int mAge;
 
    public Person(String name, int age) {
        this.mName = name;
        this.mAge = age;
    }
    
    public Person(String name) {
        this.mName = name;
    }
    
    public String GetName()
    {
        return this.mName;
    }
 
    public void ShowData() {
        System.out.println(this.mName + " " + this.mAge);
    }
 
    @Override
    public int hashCode() {
        return this.mName.hashCode();
    }
 
    @Override
    public boolean equals(Object obj) {
        Person other = (Person) obj;
        if (this.mName.equals(other.mName))
            return true;
        
        return false;
    }
}
 

 

package _1027C;
 
import java.util.HashMap;
import java.util.Scanner;
 
public class Main {
    public static void main(String[] args) {
        
        HashMap<Integer, String> map = new HashMap<Integer, String>();
        Scanner input = new Scanner(System.in);
        
        int keyInput;
        String valueInput;
        
        while(true)
        {
            System.out.print("번호와 단어를 입력하세요(99==quit): ");
            keyInput = input.nextInt();
            valueInput = input.nextLine();
            
            if(keyInput == 99) break;
            
            map.put(keyInput, valueInput.substring(1, valueInput.length()));
        }
 
        System.out.print("찾을 단어의 번호를 입력하세요: ");
        keyInput = input.nextInt();
        System.out.print(map.get(keyInput) + "입니다.");
    }
 
}