Given a binary tree, return the preorder traversal of its nodes' values. For example: Given binary tree {1,#,2,3}, return [1,2,3]. Note: Recursive solution is trivial, could you do it iteratively? 先序遍历应该是三种遍历方式中最好使用非递归来实现的了. 能够每次訪问一个节点后再将其右子节点入栈,然后左子…

这是一道将二叉树先序遍历,题目不难. 首先采用深搜递归 /** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ public class Solution { public static List<Integer> resultlist = new A…

给定一个二叉树,返回它的 前序 遍历. 示例: 输入: [1,null,2,3] 1 \ 2 / 3 输出: [1,2,3] 进阶: 递归算法很简单,你可以通过迭代算法完成吗? 递归: class Solution { public: vector<int> res; vector<int> preorderTraversal(TreeNode* root) { GetAns(root); return res; } void GetAns(TreeNode* root) { if…

144. 二叉树的前序遍历 144. Binary Tree Preorder Traversal 题目描述 给定一个二叉树,返回它的 前序 遍历. LeetCode144. Binary Tree Preorder Traversal 示例: 输入: [1,null,2,3] 1 \ 2 / 3 输出: [1,2,3] 进阶: 递归算法很简单,你可以通过迭代算法完成吗? Java 实现 Iterative Solution import java.util.LinkedList; import…

Binary Tree Preorder Traversal Given a binary tree, return the preorder traversal 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? Solution: 递归…

详见:剑指 Offer 题目汇总索引:第6题 Binary Tree Postorder Traversal            Given a binary tree, return the postorder traversal of its nodes' values. For example: Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [3,2,1]. Note: Recursive solution is trivial, could…

原题 Binary Tree Preorder Traversal 没什么好说的... 二叉树的前序遍历,当然如果我一样忘记了什么是前序遍历的..  啊啊.. 总之,前序.中序.后序,是按照根的位置来决定的,根首先访问,是前序. /** * Definition for binary tree * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(N…

二叉树的非递归前序遍历,大抵是很多人信手拈来.不屑一顾的题目罢.然而因为本人记性不好.基础太差的缘故,做这道题的时候居然自己琢磨出了一种解法,虽然谈不上创新,但简单一搜也未发现雷同,权且记录,希望于人于己皆有帮助. 估计能看到这里的读者,都是见过题目的,但还是链接原题在此:Binary Tree Preorder Traversal 二话不说,直接上代码: /** * Definition for binary tree * public class TreeNode { * int val;…

Binary Tree Preorder Traversal Given a binary tree, return the preorder traversal of its nodes' values. For example:Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [1,2,3]. c++版: /** * Definition for binary tree * struct TreeNode { * int val; * TreeNod…

144. Binary Tree Preorder Traversal Difficulty: Medium Given a binary tree, return the preorder traversal 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 it…