public class Tree {
private int data;// 数据节点
private Tree left;// 左子树
private Tree right;// 右子树
public Tree(int data) {
this.data = data;
this.left = null;
this.right = null;
}
/**
* 创建二叉树，返回根结点
*
* @param input
* @return
*/
public static Tree createTree(int[] input) {
Tree root = null;
Tree temp = null;
for (int i = 0; i < input.length; i++) {
// 创建根节点
if (root == null) {
root = temp = new Tree(input[i]);
} else {
// 回到根结点
temp = root;
// 添加节点
while (temp.data != input[i]) {
if (input[i] <= temp.data) {
if (temp.left != null) {
temp = temp.left;
} else {
temp.left = new Tree(input[i]);
}
} else {
if (temp.right != null) {
temp = temp.right;
} else {
temp.right = new Tree(input[i]);
}
}
}
}
}
return root;
}
/**
* 前序遍历
*
* @param tree
*/
public static void preOrder(Tree tree) {
if (tree != null) {
System.out.print(tree.data + " ");
preOrder(tree.left);
preOrder(tree.right);
}
}
/**
* 中序遍历
*
* @param tree
*/
public static void midOrder(Tree tree) {
if (tree != null) {
midOrder(tree.left);
System.out.print(tree.data + " ");
midOrder(tree.right);
}
}
/**
* 后序遍历
*
* @param tree
*/
public static void posOrder(Tree tree) {
if (tree != null) {
posOrder(tree.left);
posOrder(tree.right);
System.out.print(tree.data + " ");
}
}
/**
* 求二叉树的深度
*
* @param tree
*/
public static int length(Tree tree){
int depth1;
int depth2;
if(tree == null) return 0;
//左子树的深度
depth1 = length(tree.left);
//右子树的深度
depth2 = length(tree.right);
if(depth1>depth2)
return depth1+1;
else
return depth2+1;
}
/**
* @param args
*/
public static void main(String[] args) {
int[] input = { 4, 2, 6, 1, 3, 5, 7,8,10 };
Tree tree = createTree(input);
System.out.print("前序遍历：");
preOrder(tree);
System.out.print("\n二叉树深度为："+length(tree));
System.out.print("\n中序遍历：");
midOrder(tree);
System.out.print("\n后序遍历：");
posOrder(tree);
}
}
