* TreeNode(int x) : val(x), left(NULL), right(NULL) {} * };*/classSolution {public: vector<int> preorderTraversal(TreeNode*root) { vector<int>ret;if(root ==NULL)returnret; stack<TreeNode*>stk; stk.push(root);while(!stk.empty()) { TreeNode* top =stk.top(); stk.pop(); ...
01 看题和准备 今天介绍的是LeetCode算法题中Easy级别的第135题(顺位题号是589)。给定一个n-ary树,返回其节点值的前序遍历。例如,给定一个3-ary树: 1 / | \ 3 2 4 / \ 5 6 其前序遍历结果为:[1,3,5,6,2,4]。 本次解题使用的开发工具是eclipse,jdk使用的版本是1.8,环境是win7 64位系统,使...
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...
Recursive solution is trivial, could you do it iteratively? 这道题让我们求N叉树的前序遍历,有之前那道Binary Tree Preorder Traversal的基础,知道了二叉树的前序遍历的方法,很容易就可以写出N叉树的前序遍历。先来看递归的解法,主要实现一个递归函数即可,判空之后,将当前结点值加入结果res中,然后遍历子结点...
Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [1,2,3]. Note: Recursive solution is trivial, could you do it iteratively? SOLUTION1&2: 递归及非递归解法: View Code https://github.com/yuzhangcmu/LeetCode_algorithm/blob/master/tree/PreorderTraversal.java...
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]. 解法一:用栈实现(递归本质) 1/**2* Definition for a binary tree node.3* struct TreeNode {4* int val;5* TreeNode *left;6* TreeNode *...
Morris traversal ---O(n)time andO(1)space!!! Iterative solution using stack: 1vector<int> preorderTraversal(TreeNode*root) {2vector<int>nodes;3stack<TreeNode*>toVisit;4TreeNode* curNode =root;5while(curNode || !toVisit.empty()) {6if(curNode) {7nodes.push_back(curNode ->val);...
node=stack.pop() ans.append(node.val)ifnode.children: stack.extend(reversed(node.children))returnans """# Definition for a Node. class Node: def __init__(self, val, children): self.val = val self.children = children"""classSolution:defpreorder(self, root:'Node') ->List[int]:ifno...
【Inorder Traversal】 Given a binary tree, return theinordertraversal of its nodes' values. For example: Given binary tree{1,#,2,3}, 1 \ 2 / 3 return[1,3,2]. Note:Recursive solution is trivial, could you do it iteratively?
LeetCode-144-Binary Tree Preorder Traversal 算法描述: Given a binary tree, return thepreordertraversal of its nodes' values. Example: [1,null,2,3] [1,2,3] Follow up: Recursive solution is trivial, could you do it iteratively? 解题思路:先根非递归遍历。