package com.model.tree;

import java.util.ArrayDeque;
import java.util.Deque;

/**
 * @Description:测试类
 * @Author: 张紫韩
 * @Crete 2021/8/17 21:50
 * 树的遍历
 */
public class TreeDemo02 {
    public static void main(String[] args) {
        TreeNode root = new TreeNode(0);
        TreeNode left = new TreeNode(1);
        TreeNode right = new TreeNode(2);
        TreeNode  left_left = new TreeNode(3);
        TreeNode right_right = new TreeNode(4);
        root.left=left;
        root.right=right;
        left.left=left_left;
        right.right=right_right;
//        preOrder(root);
//        midOrder(root);
//        postOrder(root);
        sequenceOrder(root);

    }
// 层序遍历
    public static void sequenceOrder(TreeNode root){
        if (root==null){
            return;
        }
        Deque<TreeNode> deque=new ArrayDeque<>();
        deque.add(root);
        while (!deque.isEmpty()){
            TreeNode cur = deque.pop();
            System.out.println(cur);
            if (cur.left!=null){
                deque.add(cur.left);
            }
            if (cur.right!=null){
                deque.add(cur.right);
            }
        }
    }


//    先序遍历方式
    public static void preOrder(TreeNode root){
        if (root==null){
            return;
        }
        System.out.println(root);
        preOrder(root.left);
        preOrder(root.right);
    }

    public static void midOrder(TreeNode root){
        if (root==null){
            return;
        }
        midOrder(root.left);
        System.out.println(root);
        midOrder(root.right);
    }
    public static void postOrder(TreeNode root){
        if (root==null){
            return;
        }
        postOrder(root.left);
        postOrder(root.right);
        System.out.println(root);
    }
}