【集合Set】ListSet、TreeSet、HashSet

Thanks Modifying Code in Columbia crush on a data structure , the classic of classics.
Thanks Modifying Code in Columbia crush on a data structure , the classic of classics.
Thanks Modifying Code in Columbia crush on a data structure , the classic of classics.

Collection features:

• Do not store duplicate elements
• Commonly used in de-duplication
  • Storing new IP, new IP statistics
  • Storage vocabulary, vocabulary statistics
  • …

Interface defines a set of Set.java

Set of interface file (interface) , all collection implementations are required to implement this interface.

public interface Set<E> {
	int size();	//元素数量
	boolean isEmpty(); // 是否为空
	void claer(); // 清空集合
	boolean contains(E element); // 是否包含element元素
	void add(E element); // 添加element元素
	void remove(E element); // 删除element元素
	void traversal(Visitor<E> visitor); // 通过访问器遍历
	
	public static abstract class Visitor<E>{ // 访问器
		boolean stop;
		public abstract boolean visit(E element);
	}
}

Doubly linked list LinkedList achieve ListSet

By doubly linked list to achieve ListSet.

/**
 * LinkedList实现的ListSet
 */
public class ListSet<E> implements Set<E>{
	private LinkedList<E> list = new LinkedList<>();

	public int size() {
		return list.size();
	}

	public boolean isEmpty() {
		return list.isEmpty();
	}

	public void claer() {
		list.clear();
	}

	public boolean contains(E element) {
		return list.contains(element);
	}

	public void add(E element) {
		// if(list.contains(element)) return;
		
		int index = list.indexOf(element);
		if(index == List.ELEMENT_NOT_FOUND){ // 没有该元素
			list.add(element); // 没有就添加
		}else{
			list.set(index, element); // 已经有就替换
		}
	}

	public void remove(E element) {
		int index = list.indexOf(element);
		if(index != List.ELEMENT_NOT_FOUND){
			list.remove(index);
		}
	}

	public void traversal(Visitor<E> visitor) {
		int size = list.size();
		for(int i = 0; i < size; i++){
			visitor.visit(list.get(i));
		}
	}

}

Red-black tree RBTree achieve TreeSet

By red-black tree TreeSet implementation.

/**
 * 红黑树实现集合
 */
public class TreeSet<E> implements Set<E>{
	private RBTree<E> tree = new RBTree<>();
	
	public int size() {
		return tree.size();
	}

	public boolean isEmpty() {
		return tree.isEmpty();
	}

	public void claer() {
		tree.clear();
	}

	public boolean contains(E element) {
		return tree.contains(element);
	}

	public void add(E element) {
		tree.add(element); // 红黑树自带去重
	}

	public void remove(E element) {
		tree.remove(element);
	}

	public void traversal(Visitor<E> visitor) {
		tree.inorder(new BinaryTree.Visitor<E>() {
			@Override
			public boolean visit(E element) {
				return visitor.visit(element);
			}
		});
	}

}

TreeMap TreeSet achieved

By TreeMap implement TreeSet.

/**
 * 利用TreeMap实现TreeSet
 */
public class TreeSet<E> implements Set<E> {

	private Map<E, Object> map = new TreeMap<>();
	
	public int size() {
		return map.size();
	}

	public boolean isEmpty() {
		return map.isEmpty();
	}

	public void claer() {
		map.clear();
	}

	public boolean contains(E element) {
		return map.containsKey(element);
	}

	public void add(E element) {
		map.put(element, null);
	}

	public void remove(E element) {
		map.remove(element);
	}

	public void traversal(Visitor<E> visitor) {
		map.traversal(new Map.Visitor<E, Object>() {
			public boolean visit(E key, Object value) {
				return visitor.visit(key);
			}
		});
	}
}

HashSet HashMap achieve

By HashMap achieve TreeSet.

/**
 * 利用HashMap实现HashSet
 */
public class HashSet<E> implements Set<E> {
	private HashMap<E, Object> map = new HashMap<>();

	public int size() {
		return map.size();
	}

	public boolean isEmpty() {
		return map.isEmpty();
	}
	
	public void clear() {
		map.clear();
	}

	public boolean contains(E element) {
		return map.containsKey(element);
	}

	public void add(E element) {
		map.put(element, null);
	}

	public void remove(E element) {
		map.remove(element);
	}

	public void traversal(Visitor<E> visitor) {
		map.traversal(new Map.Visitor<E, Object>() {
			public boolean visit(E key, Object value) {
				return visitor.visit(key);
			}
		});
	}

}