需要一个长度可变的变量来存储结果。这里可以使用列表preorderlist。 从上面的分析,第一步是得到[A,A left,A right] 具体怎么做呢,需要从根节点A出发,然后将preorderList.append(A),然后应该做判断,如果存在左节点,那么就preorderList.append(A.left),如果存在右节点,就preorderList.append(A.right),那么第一...
https://leetcode.com/problems/maximum-depth-of-binary-tree/ https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/ 9. Pattern: Two Heaps,双堆类型 很多问题中,我们被告知,我们拿到一大把可以分成两队的数字。为了解决这个问题,我们感兴趣的是,怎么把数字分成两半?使得:...
题意:给一棵树,求其先根遍历的结果。思路:(1)深搜法: 1 /** 2 * Definition for a binary tree node. 3 * struct TreeNode { 4 * int val; 5 * TreeNode *left; 6 * ...
Leetcode 105 Construct Binary Tree from Preorder and Inorder Traversal (分治) Leetcode 104 Maximum Depth of Binary Tree (回溯 or 分治) Leetcode 987 Vertical Order Traversal of a Binary Tree Leetcode 1485 Clone Binary Tree With Random Pointer Leetcode 572 Subtree of Another Tree (分治) ...
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]. Note:Recursive solution is trivial, could you do it iteratively? 说明: 1)递归和非递归实现,其中非递归有两种方法 ...
Morris traversal: 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>preorderTraversal(TreeNoderoot){List<Integer>ret=newArrayList<...
preorderTraversal 函数: 这是主函数,用于执行前序遍历并返回结果数组。它首先调用 TreeSize 函数(虽然这里没有给出 TreeSize 的实现,但我们可以假设它的功能是计算树的节点数)来计算树的节点数,然后动态分配一个足够大的整数数组来存储结果。接着,它调用 _prevOrder 函数来执行前序遍历,并填充数组。最后,它设置...
@TestpublicvoidpreorderTraversal(){LeetCode144 l=newLeetCode144();//构造二叉树TreeNode root=newTreeNode(1);TreeNode node1=newTreeNode(2);TreeNode node2=newTreeNode(3);root.left=node1;node1.right=node2;//二叉树先序遍历List<Integer>nodes=l.preorderTraversal(root);nodes.stream().forEach...
Binary Tree Preorder Traversal 🟠Medium Stack, Tree Problem Set / Algorithms LeetCode 145. Binary Tree Postorder Traversal 🔴Hard Stack, Tree Problem Set / Algorithms LeetCode 198. House Robber 🟠Medium Array, Dynamic Programming Problem Set / Algorithms LeetCode 200. Number of Islands 🟠...
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