输入一个数组构建一颗二叉树，并且找出二叉树两个节点的最近公共祖先

package org.example;/*** Copyright (C), 2019-2021* author candy_chen* date 2021/8/8 19:05** &＃64;Classname test* Description: 测试*/import org.junit.Test;import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;/****/public class Foo{class TreeNode {int value;TreeNode left;TreeNode right;public TreeNode(int value) {this.value &＃61; value;}}/*** 指定节点位头结点构建二叉树* &＃64;param array* &＃64;param index* &＃64;return*/private TreeNode createBinaryTreeByArray(int[] array, int index) {TreeNode tn &＃61; null;if (index<array.length) {int value &＃61; array[index];tn &＃61; new TreeNode(value);tn.left &＃61; createBinaryTreeByArray(array, 2*index&＃43;1);tn.right &＃61; createBinaryTreeByArray(array, 2*index&＃43;2);return tn;}return tn;}TreeNode root;public TreeNode BinaryTree(int[] array) {return root &＃61; createBinaryTreeByArray(array, 0);}/*** 数组的中点构建二叉树* &＃64;param array* &＃64;return*/public TreeNode arraybuildTree(int[] array) {if (array.length &＃61;&＃61; 0) {return null;}TreeNode root &＃61; buildTree(array, 0, array.length-1);return root;}private TreeNode buildTree(int[] array, int start, int end) {if (start > end) {return null;}int mid &＃61; start &＃43; (end - start) / 2;TreeNode root &＃61; new TreeNode(array[mid]);root.left &＃61; buildTree(array, start, mid-1);root.right &＃61; buildTree(array, mid &＃43; 1, end);return root;}/*** 二叉树的最近公共祖先* 非递归实现*/Map<Integer, TreeNode> parent &＃61; new HashMap<Integer, TreeNode>();Set<Integer> visited &＃61; new HashSet<Integer>();public void dfs(TreeNode root) {if (root.left !&＃61; null) {parent.put(root.left.value, root);dfs(root.left);}if (root.right !&＃61; null) {parent.put(root.right.value, root);dfs(root.right);}}public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {dfs(root);while (p !&＃61; null) {visited.add(p.value);p &＃61; parent.get(p.value);}while (q !&＃61; null) {if (visited.contains(q.value)) {return q;}q &＃61; parent.get(q.value);}return null;}//测试&＃64;Testpublic void test() {TreeNode root &＃61; arraybuildTree(new int[]{1, 2, 3, 4, 5, 6, 7});TreeNode treeNode &＃61; lowestCommonAncestor(root, new TreeNode(3), new TreeNode(7));System.out.println(treeNode.value);}}