【Leetcode 144】的更多相关文章

C++版 - LeetCode 144. Binary Tree Preorder Traversal (二叉树先根序遍历，非递归)

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…

LeetCode 144. 二叉树的前序遍历(Binary Tree Preorder Traversal)

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…

[LeetCode] 144. Binary Tree Preorder Traversal 二叉树的先序遍历

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? 树的遍历,最常见的有先序遍历,中序遍历,后序遍历和层序遍历,它们用递归实现起来都非常的简…

Java实现 LeetCode 144 二叉树的前序遍历

144. 二叉树的前序遍历 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] /** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ class Solution { publi…

Leetcode 144. Binary Tree Preorder Traversal

参考例子:[8,3,1,6,4,7,10,14,13] 8,3,1 和 6,4 说明从root开始,沿着左臂向下寻找leaf 的过程中应该逐个将node.val push入ans. class Solution(object): def preorderTraversal(self, root): """ :type root: TreeNode :rtype: List[int] """ stack = [] ans = [] while st…

Binary Tree Preorder Traversal -- LEETCODE 144

方法一:(迭代) class Solution { public: vector<int> preorderTraversal(TreeNode* root) { vector<int> v; if(root == NULL) return v; stack<TreeNode *> s; s.push(root); TreeNode *curNode = NULL; while(!s.empty()) { curNode = s.top(); s.pop(); v.pu…

Java for LeetCode 144 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]. 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: public List<Integer> preorderTraversal(TreeNode root) { List<I…

leetcode 144. Binary Tree Preorder Traversal ----- java

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? 求前序遍历,要求不用递归.     使用双向队列.   /** * Definition…

Java [Leetcode 144]Binary Tree Preorder Traversal

题目描述: 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]. 解题思路: 这个问题最简单的方法是使用递归,但是题目规定不能使用,得使用迭代的方法. 那么我们考虑使用栈来实现. 思路是每次遍历这节点,把该点的值放入list中,然后把该点的右孩子放入栈中,并将当前点设置为左…

(二叉树 递归) leetcode 144. Binary Tree Preorder Traversal

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? ---------------------------------------------------…