classSolution {publicList<Integer> res =newArrayList<>();publicList<Integer>preorderTraversal(TreeNode root) {if(root==null)returnres; res.add(root.val); preorderTraversal(root.left); preorderTraversal(root.right);returnres;} } 非递归,迭代实现需要用栈: 首先将根节点push入栈。 在循环体中,我...
题意很简单,就是考察二叉搜索树BST的序列化和反序列化 建议和leetcode 331. Verify Preorder Serialization of a Binary Tree 二叉树的前序序列验证 和 leetcode 654. Maximum Binary Tree 构造最大二叉树 一起学习 建议和leetcode 105. Construct Binary Tree from Preorder and Inorder Traversal 中前序构造BS...
* (2)如果二叉树不为空,访问根节点,前序遍历左子树,前序遍历右子树*/publicstaticvoidpreorderTraversalRec(TreeNode root) {if(root ==null) {return; } System.out.print(root.val+ " "); preorderTraversalRec(root.left); preorderTraversalRec(root.right); }/*** 前序遍历迭代解法:用一个辅助stac...
[Leetcode-Tree]Delete Node in a BST Delete Node in a BST Given a root node reference of a BST and a key, delete the node with the given key in the BST. Return the root node reference (possibly updated) of the BST. Basically, the deletion can be divided into two stages: Search for...
1028-Recover-a-Tree-From-Preorder-Traversal 1029-Two-City-Scheduling 1030-Matrix-Cells-in-Distance-Order 1031-Maximum-Sum-of-Two-Non-Overlapping-Subarrays 1032-Stream-of-Characters 1033-Moving-Stones-Until-Consecutive 1034-Coloring-A-Border 1035-Uncrossed-Lines 1036-Esca...
if (root->lchild != NULL) post_order_traversal(root->lchild); if (root->rchild != NULL) post_order_traversal(root->rchild); // Do Something with root 广度优先遍历 又称按层次遍历, 算法借助队列实现。 LeetCode分类总结 - BST(搜索二叉树)最后...
node=stack.pop()ifpreandpre ==p:returnnode pre=node root= node.right 2) S: O(1) classSolution:definorderSuccessor(self, root, p): ans=Nonewhileroot:ifroot.val >p.val: ans=root root=root.leftelse: root=root.rightreturnans
Pop elements from the serialization list and biuld new nodes in a preorder manner. #Definition for a binary tree node.#class TreeNode(object):#def __init__(self, x):#self.val = x#self.left = None#self.right = NoneclassCodec:#Time O(n)defserialize(self, root):"""Encodes a tree...