代码如下: 1 vector<int> preorderTraversal(TreeNode* root) { 2 TreeNode* cur = root; 3 stack<TreeNode*> s; 4 vector<int> ret; 5 while(cur || !s.empty()) 6 { 7 while(cur) 8 { 9 ret.push_back(cur->val); 10 s.push(cur); 11 cur = cur->left; 12 } 13 TreeNode* top...
We run a preorder depth-first search (DFS) on therootof a binary tree. At each node in this traversal, we outputDdashes (whereDis the depth of this node), then we output the value of this node. If the depth of a node isD, the depth of its immediate child isD + 1. The depth...
leetcode7:binary-tree-preorder-traversal 题目描述 求给定的二叉树的前序遍历。 例如: 给定的二叉树为{1,#,2,3}, 1 \ 2 / 3 返回:[1,2,3]. 备注;用递归来解这道题太没有新意了,可以给出迭代的解法么? /** * struct TreeNode { * int val; * struct TreeNode *left; * struct ...
class Solution(object): def _preorderTraversal(self, root, result): if root: result.append(root.val) self._preorderTraversal(root.left, result) self._preorderTraversal(root.right, result) def preorderTraversal(self, root): """ :type root: TreeNode :rtype: List[int] """ if root ==...
*/classSolution{public:vector<int>preorderTraversal(TreeNode*root){vector<int>ans;if(!root)returnans;stack<TreeNode*>s;s.push(root);while(!s.empty()){root=();s.pop();ans.push_back(root->val);if(root->right)s.push(root->right);if(root->left)s.push(root->left);}returnans;}}...
来自专栏 · LeetCode刷题 Construct Binary Tree from Preorder and Inorder Traversal 题目描述(中等难度) 根据二叉树的先序遍历和中序遍历还原二叉树。 解法一 递归 先序遍历的顺序是根节点,左子树,右子树。中序遍历的顺序是左子树,根节点,右子树。
在对节点TreeNode的抽象中,TreeNode具有三个属性,分别是val、left和right,val表示节点的值,而left和right分别指向左右两个子节点(默认为None)。 image.png 思路 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] ...
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<...
* 题目: 105.Construct Binary Tree from Preorder and Inorder Traversal * 网址:https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/ * 结果:AC * 来源:LeetCode * 博客: ---*/#include<iostream>#include<vector>#include<algorithm>usingnamespacestd;structTree...
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...Leet...