链式存储二叉树（java）

//二叉树（链式存储）
import java.util.ArrayDeque;

import java.util.LinkedList;
import java.util.List;
import java.util.Queue;
import java.util.Stack;

public class MyTree {
	static Node root;
	class Node{
		private Node lChild;
		private Node rChild;
		private int data;
		Node(int d){
			data=d;
		}
		public Node getlChild() {
			return lChild;
		}
		public void setlChild(Node lChild) {
			this.lChild = lChild;
		}
		public Node getrChild() {
			return rChild;
		}
		public void setrChild(Node rChild) {
			this.rChild = rChild;
		}
		public int getData() {
			return data;
		}
		public void setData(int data) {
			this.data = data;
		}
		
	}
	//创建二叉树
	Node creatTree(int[] a){
		List<Node> nodelist = new LinkedList<>();
		for(int i=0;i<a.length;i++){
			nodelist.add(new Node(a[i]));
		}
		for(int i=0;i<a.length/2-1;i++){
			nodelist.get(i).setlChild(nodelist.get(2*i+1));
			nodelist.get(i).setrChild(nodelist.get(2*i+2));
		}
		int index = a.length/2-1;
		nodelist.get(index).setlChild(nodelist.get(2*index+1));
		if(a.length%2==1){
			nodelist.get(index).setrChild(nodelist.get(2*index+2));
		}
		root=nodelist.get(0);
		return root;
	}
	
	//先序遍历
	void preOrder(Node n){
		if(n==null){
			return;
		}
		System.out.print(n.getData()+" ");
		preOrder(n.getlChild());
		preOrder(n.getrChild());
	}
	//求高度
	int getHeight(Node n){
		if(n==null){
			return 0;
		}else
			{
			int	left = getHeight(n.getlChild());
			int right = getHeight(n.getrChild());
			return 1+Math.max(left, right);// 每向上返回一层，加一
					}
		}
	//深度优先遍历（dfs）
	void dfsOrder(){
		if(root==null){
			System.out.println("empty tree");
			return;
		}
		Stack<Node>stack=new Stack<>();
		stack.push(root);
		while(!stack.isEmpty()){
			Node node = stack.pop();
			System.out.print(node.getData()+" ");
			if(node.getrChild()!=null){
				stack.push(node.getrChild());
			}
			if(node.getlChild()!=null){
				stack.push(node.getlChild());
			}
		}
	}
	//广度优先遍历（bfs）
	void bfsOrder(){
		if(root==null){
			System.out.println("empty tree");
		}
		Queue<Node>queue=new ArrayDeque<>();
		queue.add(root);
		while(!queue.isEmpty()){
			Node n = queue.remove();
			System.out.print(n.getData()+" ");
			if(n.getlChild()!=null){
				queue.add(n.getlChild());
			}
			if(n.getrChild()!=null){
				queue.add(n.getrChild());
			}
		}
	}
	//求树的宽度
	int getWeight(Node n){
		if(n==null){
			return 1;
		}
		Queue<Node>queue = new ArrayDeque<>();
		queue.add(n);
		int maxsize=1;//最大长度
		while(true){
			int len = queue.size();//当前层节点数
			if(len==0){
				break; //跳出
			}while(len>0){ //如果还有当前层节点
				Node node = queue.poll();
				len--;
				if(node.getlChild()!=null){
					queue.add(node.getlChild());
				}if(node.getrChild()!=null){
					queue.add(node.getrChild());
				}
			}
			maxsize = Math.max(maxsize, queue.size());//新入队之前最大的宽度与新入队的大小取较大值
			
		}
		return maxsize;
				
	}
	}

public static void main(String[] args) {
		int[] arr = {1,2,3,4,78,6,7,8,9};
		MyTree m = new MyTree();
		Node node = m.creatTree(arr);
		m.preOrder(node);
		System.out.println();
		System.out.println("该树高度为"+m.getHeight(root));
		System.out.println("深度优先遍历:");
		m.dfsOrder();
		System.out.println();
		System.out.println("广度优先遍历：");
		m.bfsOrder();
		System.out.println();
		System.out.println("该树的宽度为："+m.getWeight(root));
	}