前言

【LeetCode 题解】系列传送门： http://www.cnblogs.com/double-win/category/573499.html

1.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].

Note: Recursive solution is trivial, could you do it iteratively?

2. 题意

先序遍历二叉树，递归的思路是普通的，能否用迭代呢？

3. 思路

非递归思路：<借助stack>

    vector<int> preorderTraversal(TreeNode *root) {stack<TreeNode* > st;vector<int> vi;vi.clear();if(!root) return vi;st.push(root);while(!st.empty()){TreeNode *tmp = st.top();vi.push_back(tmp->val);    st.pop();if(tmp->right) st.push(tmp->right);if(tmp->left) st.push(tmp->left);}return vi;}

递归思路：

class Solution {
private:vector<int> vi;
public:vector<int> preorderTraversal(TreeNode *root) {vi.clear();if(!root) return vi;preorder(root);return vi;}void preorder(TreeNode* root){if(!root) return;vi.push_back(root->val);preorder(root->left);preorder(root->right);}
};

4.相关题目

(1)二叉树的中序遍历:

(2)二叉树的后序遍历:

(3) 二叉树系列文章:

作者：Double_Win

出处: http://www.cnblogs.com/double-win/p/3896010.html

声明：由于本人水平有限，文章在表述和代码方面如有不妥之处，欢迎批评指正~

转载于:https://www.cnblogs.com/double-win/p/3895822.html

[LeetCode 题解]: Binary Tree Preorder Traversal相关推荐

【二叉树迭代版前序遍历】LeetCode 144. Binary Tree Preorder Traversal
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 ...
[Lintcode]66. Binary Tree Preorder Traversal/[Leetcode]144. Binary Tree Preorder Traversal
66. Binary Tree Preorder Traversal/144. Binary Tree Preorder Traversal 本题难度: Easy/Medium Topic: Bina ...
leetcode 144. Binary Tree Preorder Traversal
Given a binary tree, return the preorder traversal of its nodes' values. For example: Given binary t ...
Leetcode - 144. Binary Tree Preorder Traversal (层次遍历)
Given a binary tree, return the preorder traversal of its nodes' values. Example: Input: [1,null,2,3 ...
leetcode 144. Binary Tree Preorder Traversal ----- java
Given a binary tree, return the preorder traversal of its nodes' values. For example: Given binary t ...
[LeetCode] 144. Binary Tree Preorder Traversal Java
题目: Given a binary tree, return the preorder traversal of its nodes' values. For example: Given bina ...
LeetCode 145. Binary Tree Postorder Traversal
原题链接在这里:https://leetcode.com/problems/binary-tree-postorder-traversal/ 题目: Given a binary tree, retu ...
LeetCode 144. Binary Tree Preorder Traversal--二叉树前序遍历--反向压栈--迭代-栈，递归--C++,Python解法
题目地址:Binary Tree Preorder Traversal - LeetCode Given a binary tree, return the preorder traversal of ...
LeetCode：144_Binary Tree Preorder Traversal | 二叉树的前序遍历 | Medium
题目:Binary Tree Preorder Traversal 二叉树的前序遍历,同样使用栈来解,代码如下: 1 struct TreeNode { 2 int val; 3 TreeNode* ...

[LeetCode 题解]: Binary Tree Preorder Traversal

前言

1.题目描述

2. 题意

3. 思路

4.相关题目

[LeetCode 题解]: Binary Tree Preorder Traversal相关推荐

最新文章

热门文章