zoukankan      html  css  js  c++  java
  • 求二叉树的高度

    思想:

    (1) 方法一: 递归

    (2) 方法二: 分层遍历。遍历的层数即高度

    package com.zhaochao.tree;

    /**
    * Created by zhaochao on 17/1/23.
    */
    public class DepthOfBTree {

    public int depthOfTree(TreeNode root) {
    if(root == null) {
    return 0;
    }
    int leftDepth = depthOfTree(root.left);
    int rightDepth = depthOfTree(root.right);
    return Math.max(leftDepth, rightDepth) + 1;
    }

    public static void main(String[] args) {
    TreeNode root = new TreeNode(0);
    TreeNode node1 = new TreeNode(1);
    TreeNode node2 = new TreeNode(2);
    TreeNode node3 = new TreeNode(3);

    root.left = node1;
    root.right = node2;
    node2.left = node3;

    DepthOfBTree test = new DepthOfBTree();
    int length = test.depthOfTree(root);

    System.out.println(length);
    }

    }



    方法二:

    package com.zhaochao.tree;

    import java.lang.reflect.Array;
    import java.util.ArrayList;
    import java.util.LinkedList;
    import java.util.List;
    import java.util.Queue;

    /**
    * Created by zhaochao on 17/1/23.
    */
    public class LeverTraversal {

    public int depth = 0;
    public ArrayList<List<Integer>> leverOrder(TreeNode root) {

    ArrayList<List<Integer>> result = new ArrayList<List<Integer>>();

    if(root == null) {
    return result;
    }

    Queue<TreeNode> queue = new LinkedList<TreeNode>();
    queue.add(root);


    while(!queue.isEmpty()) {
    List<Integer> lever = new ArrayList<Integer>();
    int size = queue.size();
    depth++;
    for(int i = 0; i < size; i++) {
    TreeNode head = queue.poll();
    lever.add(head.val);
    if(head.left != null) {
    queue.add(head.left);
    }
    if(head.right != null) {
    queue.add(head.right);
    }
    }
    result.add(lever);
    }

    return result;
    }

    public static void main(String[] args) {

    TreeNode root = new TreeNode(0);
    TreeNode node1 = new TreeNode(1);
    TreeNode node2 = new TreeNode(2);
    TreeNode node3 = new TreeNode(3);

    root.left = node1;
    root.right = node2;
    node2.left = node3;

    LeverTraversal test = new LeverTraversal();
    ArrayList<List<Integer>> result = new ArrayList<List<Integer>>();
    result = test.leverOrder(root);
    for(int i = 0; i < result.size(); i++) {
    List<Integer> tmp = new ArrayList<Integer>();
    tmp = result.get(i);
    for(int j = 0; j < tmp.size(); j++) {
    System.out.print(tmp.get(j) + " ");
    }
    System.out.println();
    }
    System.out.println("The depth of the binary tree is : " + test.depth);
    }
    }
  • 相关阅读:
    SLS评测报告
    Flash对不同的浏览器的兼容性
    NodeJS的Cluster模块使用
    Varnish+Xcache构建高性能WEB构架初探
    Memcached Client的释疑
    Firebug及YSlow简介与使用图文详解
    PHP Memcached 实现简单数据库缓存
    PHP + Memcache 实现Session共享
    Linux 开机关机在线求助与指令输入
    Linux 基础学习篇笔记 Linux基础知识
  • 原文地址:https://www.cnblogs.com/superzhaochao/p/6345134.html
Copyright © 2011-2022 走看看