/* * Java实现二叉树 */public class BinaryTree {	int treeNode;	BinaryTree leftTree;	BinaryTree rightTree;		public BinaryTree(int Data) {		// TODO Auto-generated constructor stub		treeNode=Data;		leftTree=null;		rightTree=null;	}		public void insert(BinaryTree node,int data) {		if(data >node.treeNode){			if(node.rightTree==null){				rightTree=new BinaryTree(data);			}else{				this.insert(node.rightTree, data);			}		}else{			if (node.leftTree==null) {				leftTree=new BinaryTree(data);			}else{				this.insert(node.leftTree, data);			}		}	}}

 

/* * 对定义二叉树的，先序遍历，中序遍历，后序遍历 */public class BinaryTreeOrder {	public static void preOrder(BinaryTree root) { // 先序遍历		if (root != null) {			System.out.print(root.treeNode + "-");			preOrder(root.leftTree);			preOrder(root.rightTree);		}	}	public static void inOrder(BinaryTree root) { // 中序遍历		if (root != null) {			inOrder(root.leftTree);			System.out.print(root.treeNode + "--");			inOrder(root.rightTree);		}	}	public static void postOrder(BinaryTree root) { // 后序遍历		if (root != null) {			postOrder(root.leftTree);			postOrder(root.rightTree);			System.out.print(root.treeNode + "---");		}	}	public static void main(String[] args) {		int[] array = { 12, 76, 35, 22, 16, 48, 90, 46, 9, 40 };		BinaryTree root = new BinaryTree(array[0]); // 创建二叉树		for (int i = 1; i < array.length; i++) {			root.insert(root, array[i]); // 向二叉树中插入数据		}		System.out.println("先序遍历：");		preOrder(root);		System.out.println();		System.out.println("中序遍历：");		inOrder(root);		System.out.println();		System.out.println("后序遍历：");		postOrder(root);	}}