当前节点更新为当前节点的右孩子。 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) ...
1#Definition for a binary tree node.2#class TreeNode(object):3#def __init__(self, x):4#self.val = x5#self.left = None6#self.right = None78classSolution(object):9defpreorderTraversal(self, root):10"""11:type root: TreeNode12:rtype: List[int]13"""14ifnotroot: # 为空直接返回...
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] 具体怎么做呢,需要从根节点A出发,然后将preorderList.append(A),然后应该做判断,如果存在左节点,那么就preorderList.append(A.left),如果存在右节点,就preorderList.append(A.right),那么第一...
*/voidtraversal(structTreeNode*root,int*index,int*res){if(!root)return;res[(*index)++]=root->val;traversal(root->left,index,res);traversal(root->right,index,res);}int*preorderTraversal(structTreeNode*root,int*returnSize){int*res=malloc(sizeof(int)*110);intindex=0;traversal(root,&index,...
144. Binary Tree Preorder Traversal(二叉树的前序遍历) 题目地址:https://leetcode.com/problems/binary-tree-preorder-traversal/description/ Given a binary tree, return thepreordertraversal of its nodes' values. Example: Input:[1,null,2,3]1 \ 2 / 3Output:[1,2,3]...
其实递归本质上是在利用栈的性质,每次递归都是将一个函数压入栈中。 所以我们可以用循环和栈模拟递归 class Solution { public: TreeNode* s[100005]; vector<int> ans; int tag=0; vector<int> preorderTraversal(TreeNode* root) { if(root==NULL) return ans; ...
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...144...
[leetcode] 105. Construct Binary Tree frompreorderandinorderTraversal Description Given preorder and inorder traversal of a tree, construct the binary tree. Note: You may assume that duplicates do not exist in the tree. For example, given ...
LeetCode Binary Tree Preorder Traversal /** * Definition for binary tree * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: vector<int> preorderTraversal(TreeNode *...
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