1/**2* Definition for a binary tree node.3* struct TreeNode {4* int val;5* TreeNode *left;6* TreeNode *right;7* TreeNode(int x) : val(x), left(NULL), right(NULL) {}8* };9*/10classSolution {11public:12vector<int> preorderTraversal(TreeNode*root) {13vector<int>rVec;14pr...
1/**2* Definition for binary tree3* struct TreeNode {4* int val;5* TreeNode *left;6* TreeNode *right;7* TreeNode(int x) : val(x), left(NULL), right(NULL) {}8* };9*/10classSolution {11public:12vector<int> preorderTraversal(TreeNode *root) {13//IMPORTANT: Please reset any...
LeetCode 144. Binary Tree Preorder Traversal Solution1:递归版 二叉树的前序遍历递归版是很简单的,前序遍历的迭代版相对是最容易理解的。 迭代版链接:https://blog.csdn.net/allenlzcoder/article/details/79837841 Solution2:迭代版 前序遍历也是最简单的一种,分为下面三个步骤: 1...144. 二叉树的前序遍...
Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example: Given binary tree [3,9,20,null,null,15,7], 代码语言:javascript 代码运行次数:0 运行 AI代码解释 ...
Given a binary tree, return the preorder traversal of its nodes' values. Example: Input: [1,null,2,3] 1 2 / 3 Output: [1,2,3] Follow up: Recursive solution is trivial, could you do it iteratively? 翻译 给出一棵二叉树,返回其节点值的前序遍历。
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<...
inorder_root-1);// 递归地构造右子树,并连接到根节点// 先序遍历中「从 左边界+1+左子树节点数目 开始到 右边界」的元素就对应了中序遍历中「从 根节点定位+1 到 右边界」的元素root.right=myBuildTree(preorder,inorder,preorder_left+size_left_subtree+1,preorder_right,inorder_root+1,inorder_...
Binary Tree Preorder Traversal 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]. 1classSolution {2public:3vector<int> preorderTraversal(TreeNode *root) {4vector<int>result;5stack<TreeNode *>...
144Binary Tree Preorder TraversalPython1. Recursion, O(n) and O(n) 2. Stack, O(n) and O(n) 145Binary Tree Postorder TraversalPython1. Recursion, O(n) and O(n) 2. Stack and queue (insert 0), O(n) and O(n) 3. Stack and isinstance(curr, TreeNode), O(n) and O(n) ...
Leetcode 144 binary tree preorder traversal 下面这种写法使用了一个辅助结点p,这种写法其实可以看作是一个模版,对应的还有中序和后序的模版写法,形式很统一,方便于记忆。 辅助结点p初始化为根结点,while循环的条件是栈不为空或者辅助结点p不为空,在循环中首先判断如果辅助结点p存在,那么先将p加入栈中,然后将...