java数据结构二叉树

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本文链接： https://blog.csdn.net/weixin_42558056/article/details/98883351

二叉树(java)

数组实现

//数组实现二叉树
public class ArrayTree <T>{
private T[] data;
private int deep;
private int MaxSize;
private int size=0;
public ArrayTree(int deep) {
	this.deep=deep;
	MaxSize=(int)Math.pow(2,deep)-1;
	data=(T[])new Object[MaxSize];
}
public void creatRoot(T value) {
	data[0]=value;
	size++;
}
public void add(T value,int index,boolean left) {
	if(data[index]==null) {
		throw new RuntimeException(index+":null");
	}
	if(2*index+1>=MaxSize) {
		throw new RuntimeException("array full");
	}
	if(left) {
		data[2*index+1]=value;
		size++;
		}else {
			data[2*index+2]=value;
			size++;
		}
}
public boolean inEmpty() {
	return data[0]==null;
}
public int size() {
	return this.size;
}
public String toString() {
	String str="";
	for(int i=0;i<MaxSize;i++) {
		str=str+data[i]+" ";
	}
	return str;
}
public static void main(String[] args) {
	ArrayTree<String> tree=new ArrayTree<String>(3);
	tree.creatRoot("A");
	  tree.add("B", 0, true);
      tree.add("C", 0, false);
      tree.add("E", 1, false);
      tree.add("G", 2, true);
      tree.add("H", 2, false);
      System.out.println(tree.toString());
      System.out.println(tree.size);
	
	
}

}

运行结果：

链表实现

import java.util.ArrayList;
import java.util.List;
public class NodeTree<T> {
class Node<T>{
	public Node left;//左子树
	public Node right;//右子树
	public T data;
	public Node(T data) {
		this.data=data;
		this.left=null;
		this.right=null;
	}
	public Node() {};
}
	private Node root;
	private int size=0;
	public void createRoot(T value) {
		if(value==null) {
			throw new RuntimeException("root is null");
		}
		Node<T> newNode=new Node<T>(value);
		this.root=newNode;
		size++;
		}
	public Node getRoot() {
		if(root==null) {
			throw new RuntimeException("root is null");
			}
		return this.root;
	}
	public boolean isEmpty() {
		return root==null;
	}
	public Node add(Node<T> n,T value,boolean left) {
		if(value==null) {
			throw new RuntimeException("子节点为空");
			}
		if(n==null) {
			throw new RuntimeException("父节点为空");
		}
		Node<T> newNode=new Node<T>(value);
		if(left) {
			if(n.left!=null) {
				throw new RuntimeException("已有左子节点");
			}
			n.left=newNode;
			size++;
			return newNode;
		}else {
			if(n.right!=null) {
				throw new RuntimeException("已有子右节点");
			}
			n.right=newNode;
			size++;
			return newNode;
			}
		}
public static void main(String[] args) {
	NodeTree<String> tree=new NodeTree();
	tree.createRoot("A");
	NodeTree.Node node1=tree.add(tree.root, "B",true);
	NodeTree.Node node2=tree.add(tree.root, "C",false);
	NodeTree.Node node3=tree.add(node1, "D",false);
	NodeTree.Node node4=tree.add(node2, "E",true);
	NodeTree.Node node5=tree.add(node2, "F",true);
	}
}