TreeNode(intx) { val = x; } } 第一种方法:算法实现类 importjava.util.LinkedList;importjava.util.List;publicclassSolution{privateList<Integer> result;publicList<Integer>preorderTraversal(TreeNode root){ result =newLink
Given a binary tree, return thepreordertraversal of its nodes' values. For example: Given binary tree{1,#,2,3}, 1 \ 2 / 3 return[1,2,3]. 二叉树的前序遍历,根节点→左子树→右子树 解题思路一: 递归实现,JAVA实现如下: 1 2 3 4 5 6 7 8 9 publicList<Integer> preorderTraversal(Tr...
Can you solve this real interview question? Binary Tree Preorder Traversal - Given the root of a binary tree, return the preorder traversal of its nodes' values. Example 1: Input: root = [1,null,2,3] Output: [1,2,3] Explanation: [https://assets.l
public TreeNode buildTree(int[] preorder, int[] inorder) { if(preorder.length == 0 || inorder.length == 0) return null; return helper(0,inorder.length - 1,preorder,inorder); } private TreeNode helper(int inStart, int inEnd, int[] preorder, int[] inorder){ // Base情况 if...
The function returns the root of the constructed binary tree. 4. Time & Space Complexity Analysis: 4.1 Time Complexity: 4.1.1 Lists as parameters In each recursive call, the index() function is used to find the index of the root value in the inorder traversal list. This function has a ...
My code: importjava.util.ArrayList;importjava.util.List;/** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */publicclassSolution{public List<Integer>preorderTraversal(TreeNode root...
145. 二叉树的后序遍历 - 给你一棵二叉树的根节点 root ,返回其节点值的 后序遍历 。 示例 1: 输入:root = [1,null,2,3] 输出:[3,2,1] 解释: [https://assets.leetcode.com/uploads/2024/08/29/screenshot-2024-08-29-202743.png] 示例 2: 输入:root =
102. 二叉树的层序遍历 - 给你二叉树的根节点 root ,返回其节点值的 层序遍历 。 (即逐层地,从左到右访问所有节点)。 示例 1: [https://assets.leetcode.com/uploads/2021/02/19/tree1.jpg] 输入:root = [3,9,20,null,null,15,7] 输出:[[3],[9,20],[15,7]]
名字叫做, morrois traversal, 自己写了下: My code: /** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */publicclassSolution{publicList<Integer>inorderTraversal(TreeNoderoot){List...
return its zigzag level order traversal as: [ [3], [20,9], [15,7] ] 在102的基础上稍加改动即可 1. 2. 3. 4. 5. 6. 7. 8. class Solution { public: vector<vector<int>> zigzagLevelOrder(TreeNode* root) { queue<TreeNode*> q; ...