DS树+图综合练习--二叉树高度

题目描述

给出一棵二叉树，求它的高度。二叉树的创建采用前面实验的方法。

注意，二叉树的层数是从1开始

输入

第一行输入一个整数t，表示有t个二叉树

第二行起输入每个二叉树的先序遍历结果，空树用字符‘0’表示，连续输入t行

输出

每行输出一个二叉树的高度

样例输入

1

AB0C00D00

样例输出

3

提示

import java.util.*;

/**
 * @author: Liu Canbin
 * @date: 2019/1/4
 */

public class Main {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        for (int i = 0; i <n ; i++) {
            String s = scanner.next();
            Tree tree = new Tree();
            tree.create(s);
            tree.treeDepthShow();
//            System.out.println();
        }

    }
}

class Node
{
    char data;
    Node left;
    Node right;
    Node(char ch){
        data =ch;
        left = null;
        right = null;
    }

    public void setLeft(Node left) {
        this.left = left;
    }

    public void setRight(Node right) {
        this.right = right;
    }
}

class Tree{
    Node root;
    int pos;
    String strTree;
    int sum;

    void create(String s){
        pos = 0;
        strTree = s;
        sum =0;
        root =createTree();
    }

    Node createTree(){
        Node t;
        char ch = strTree.charAt(pos++);
        if (ch=='0'){
            t = null;
        }else {
            t = new Node(ch);
            t.setLeft(createTree());
            t.setRight(createTree());
        }
        return t;
    }

    void treeDepthShow() {
        System.out.println(treeDepth(root));
    }

    private int treeDepth(Node t){
       if (t==null){
            return 0;
       }
       int left = treeDepth(t.left);
       int right = treeDepth(t.right);
       return left>right?left+1:right+1;
    }
}