TreeSet<E> treeSet = new TreeSet<E>();
TreeSet<String> treeSet = new TreeSet<>();

public class TreeSetExample{
    public static void main(String[] args) {
        TreeSet<Integer> scores = new TreeSet<>();
        scores.add(87);
        scores.add(98);
        scores.add(75);
        scores.add(95);
        scores.add(80);

        Integer score =null;

        //가장 낮은 값의 객체 리턴
        score = scores.first();
        System.out.println("가장 낮은 점수: "+ score);

        //가장 높은 값의 객체 리턴
        score = scores.last();
        System.out.println("가장 높은 점수: "+ score);

        score = scores.lower(95);
        System.out.println("95점 아래 점수: "+ score);

        score = scores.higher(95);
        System.out.println("95점 위 점수: "+ score);

        score = scores.floor(95);
        System.out.println("95점이거나 아래인 점수: "+ score);

        score = scores.ceiling(85);
        System.out.println("85점이거나 위인 점수: " +score);

        System.out.println();
        System.out.println("====================================");
        while(!scores.isEmpty()){
            int sc = scores.pollFirst(); //가장 낮은 값 꺼내고 삭제. 오름차순
            System.out.println("꺼낸 값: " + sc);
            System.out.println("남은 객체수: "+ scores.size());
        }
    }
}

NavigableSet<E> descendingSet = treeSet.descendingSet();
NavigableSet<E> ascendingSet = descendingSet.descendingSet(); // 두번 호출

public class TreeSetExample2 {
    public static void main(String[] args) {
        TreeSet<Integer> scores = new TreeSet<>();
        scores.add(50);
        scores.add(60);
        scores.add(70);
        scores.add(80);
        scores.add(90);

        Iterator<Integer> iterator = scores.descendingIterator();
        while(iterator.hasNext()){
           Integer score = iterator.next();
            System.out.println(score +" ");
        }

        System.out.println();

        NavigableSet<Integer> descendingSet = scores.descendingSet();
        for(Integer score: descendingSet)
            System.out.println(score +" ");


        System.out.println();
        NavigableSet<Integer> ascendingSet = descendingSet.descendingSet();
        for(Integer score: ascendingSet){
            System.out.println(score +" ");
        }
    }
}

public class TreeSetExample3 {
    public static void main(String[] args) {
        TreeSet<String> treeSet = new TreeSet<>();
        treeSet.add("apple");
        treeSet.add("forever");
        treeSet.add("description");
        treeSet.add("ever");
        treeSet.add("zoo");
        treeSet.add("base");
        treeSet.add("guess");
        treeSet.add("cherry");
        treeSet.add("chic");

        System.out.println("[c~f 사이의 단어 검색]");
        NavigableSet<String> rangeSet = treeSet.subSet
                ("c",true,"f",true);

        for(String word: rangeSet){
            System.out.println(word);
        }
    }
}

TreeMap<K,V> treeMap = new TreeMap<K,V>();
TreeMap<String, Integer> treeMap = new TreeMap<>();

import java.util.Map;
import java.util.TreeMap;

public class TreeMapExample1 {
    public static void main(String[] args) {
        TreeMap<Integer,String> scores = new TreeMap<>();
        scores.put(87,"홍길동");
        scores.put(98,"이동수");
        scores.put(75,"박길순");
        scores.put(95,"신용권");
        scores.put(80,"김자바");

        Map.Entry<Integer,String> entry = null;

        entry = scores.firstEntry(); //가장 낮은 키의 entry.
        System.out.println("가장 낮은 점수: " + entry.getKey() +" -" + entry.getValue());

        entry = scores.lastEntry(); //가장 큰 키의 entry
        System.out.println("가장 큰 점수: " + entry.getKey() +" -"+ entry.getValue());

        entry = scores.lowerEntry(95);
        System.out.println("95점 아래 점수: " +entry.getKey() +" -" + entry.getValue());

        entry = scores.higherEntry(95);
        System.out.println("95점 위 점수: " + entry.getKey() +" -"+entry.getValue());

        entry = scores.floorEntry(95);
        System.out.println("95점이거나 아래인 점수: "+ entry.getKey() +" -" +entry.getValue());

        entry = scores.ceilingEntry(85);
        System.out.println("85점이거나 바로 위의 점수: " +entry.getKey()+ " -" +entry.getValue());

        System.out.println();
        while(!scores.isEmpty()){
           entry = scores.pollFirstEntry(); // 오름차순
           System.out.println("받은 점수: "+entry.getKey()+ " 사람: "+entry.getValue());
            System.out.println("남은 객체 수: " + scores.size());
        }
    }
}

NavigableMap<K,V> descendingMap = treeMap.descendingMap();//내림차순
NavigableMap<K,V> ascendingMap = descendingMap.descendingMap(); //오름차순

package CollectionFramework.Tree;

import java.util.*;

public class TreeMapExample2 {
    public static void main(String[] args) {
        TreeMap<Integer,String> scores = new TreeMap<>();
        scores.put(87,"홍길동");
        scores.put(93,"이동수");
        scores.put(75,"박길순");
        scores.put(95,"신용권");
        scores.put(80,"김자바");

        Set<Map.Entry<Integer,String>> entrySet2 = scores.entrySet();
        for(Map.Entry<Integer,String> entry: entrySet2){
            System.out.println(entry.getKey() +"-" + entry.getValue());
        }
        System.out.println();


        NavigableSet<Integer> descendingKeySet = scores.descendingKeySet();
        System.out.println("[내림차순]");
        for(Integer score: descendingKeySet){
            System.out.print("받은 점수: " + score);
            System.out.println(" 사람: " + scores.get(score));
        }
        System.out.println();
        System.out.println("[내림차순]");
        //오름차순
        //Map은 for문을 돌릴 수 없으므로 Set을 활용하자.
        NavigableMap<Integer,String> descendingMap = scores.descendingMap();
        Set<Map.Entry<Integer,String>> entrySet = descendingMap.entrySet();
        for(Map.Entry<Integer,String> entry :entrySet){
            System.out.println(entry.getKey() +"-"+ entry.getValue());
        }

        //내림차순
        System.out.println();
        System.out.println("[오름차순]");
        descendingMap = descendingMap.descendingMap();
        entrySet = descendingMap.entrySet();
        for(Map.Entry<Integer,String> entry :entrySet){
            System.out.println(entry.getKey() +"-"+ entry.getValue());
        }

    }
}

public class TreeMapExample3 {
    public static void main(String[] args) {
        TreeMap<String,Integer> treeMap = new TreeMap<>();
        treeMap.put("apple",10);
        treeMap.put("forever",60);
        treeMap.put("description",40);
        treeMap.put("ever",50);
        treeMap.put("zoo",10);
        treeMap.put("base",20);
        treeMap.put("guess",70);
        treeMap.put("cherry",30);
        treeMap.put("chic",25);

        System.out.println("[c~f 사이의 단어 검색]");
        NavigableMap<String,Integer> navigableMap = treeMap.subMap
                ("c",true,"f",true);
        Set<Map.Entry<String,Integer>> entrySet = navigableMap.entrySet();

        for(Map.Entry<String,Integer> entry: entrySet){
            System.out.print("word: " + entry.getKey());
            System.out.println(" number: " + entry.getValue());
        }
    }
}

public class Person implements Comparable<Person> {

    String name;
    int age;
    
    Person(String name, int age){
        this.name = name;
        this.age = age;
    }
    
    @Override
    //나이로 비교하는 것으로 설정
    public int compareTo(Person o) {
        if(age<o.age) return -1;
        else if(age == o.age) return  0;
        else
            return 1;
    }
}

public class ComparableExample {
    public static void main(String[] args) {
        TreeSet<Person> treeSet = new TreeSet<>();

        treeSet.add(new Person("KIM", 27));
        treeSet.add(new Person("GYU",26));
        treeSet.add(new Person("LEE",24));

        System.out.println("[나이 오름차순]");
        for(Person person: treeSet){
            System.out.println(person.name +"-" + person.age);
        }
    }
}

TreeSet<E> treeSet = new TreeSet<E>(new AscendingComparator() ); //오름차순 정렬자
TreeSet<E> treeSet = new TreeSet<E>(new DescendingComparator() );//내림차순 정렬자

public class ComparatorExample {
    public static void main(String[] args) {
        //fruit의 가격을 기준으로(getPrice) Comparator 작성.
        Comparator<Fruit> comparator = (o1,o2)->{
            //큰것이 앞에 오도록
            if(o1.getPrice()>o2.getPrice())
                return -1;
            //작은 것이 뒤에 가도록
            else if(o1.getPrice()<o2.getPrice())
                return 1;
            else
                return 0;
        };

        TreeSet<Fruit> treeSet = new TreeSet<>(comparator); //내림차순 정렬
        treeSet.add(new Fruit("포도",3000));
        treeSet.add(new Fruit("수박",10000));
        treeSet.add(new Fruit("딸기", 6000));

        Iterator<Fruit> iterator = treeSet.iterator();
        while(iterator.hasNext()){
            Fruit fruit = iterator.next();
            System.out.print("과일 이름: " + fruit.getName());
            System.out.println(" 가격: "+ fruit.getPrice());
        }
    }
}
/*실행결과 
과일 이름: 수박 가격: 10000
과일 이름: 딸기 가격: 6000
과일 이름: 포도 가격: 3000
*/