Level up your coding skills and quickly land a job. This is the best place to expand your knowledge and get prepared for your next interview.
Can you solve this real interview question? Binary Search Tree Iterator - Implement the BSTIterator class that represents an iterator over the in-order traversal [https://en.wikipedia.org/wiki/Tree_traversal#In-order_(LNR)] of a binary search tree (BST):
* TreeNode(int x) { val = x; } * }*/publicclassBSTIterator {//TreeNode root;Stack<TreeNode> stack =newStack<TreeNode>();publicBSTIterator(TreeNode root) { pushLeft(root); }/** @return whether we have a next smallest number*/publicboolean hasNext() {return!stack.isEmpty(); }/*...
题目链接: Binary Search Tree Iterator : leetcode.com/problems/b 二叉搜索树迭代器: leetcode-cn.com/problem LeetCode 日更第 95 天,感谢阅读至此的你 欢迎点赞、收藏鼓励支持小满 发布于 2022-04-25 09:24 力扣(LeetCode) Python 算法 赞同添加评论 分享喜欢收藏申请转载 ...
Implement an iterator over a binary search tree (BST). Your iterator will be initialized with the root node of a BST. Callingnext()will return the next smallest number in the BST. Note:next()andhasNext()should run in average O(1) time and uses O(h) memory, wherehis the height of ...
Given a binary search tree (BST), find the lowest common ancestor (LCA) of two given nodes in the BST.According to the definition of LCA on Wikipedia:“The lowest common ancestor is defined between two nodes p and q as the lowest node in T that has both p and q as descendants (wher...
二叉搜索树(Binary Search Tree,简写 BST)是一种比较特别的二叉树。它需要满足: 1.任意节点的值大于其左子树下的所有节点; 2.任意节点的值小于其右子树下的所有节点; 下图就是一个二叉搜索树。 之所以叫二叉搜索树,因为它搜索效率很高,时间复杂度为 O(log n),对标数组的二分查找。
Given the tree: 4 / \ 2 7 / \ 1 3 And the value to insert: 5 1. 2. 3. 4. 5. 6. 7. You can return this binary search tree: 4 / \ 2 7 / \ / 1 3 5 1. 2. 3. 4. 5. This tree is also valid: 5 / \
* TreeNode(int x) { val = x; } * } */publicclassBSTIterator{Stack<TreeNode>s;publicBSTIterator(TreeNoderoot){s=newStack<TreeNode>();while(root!=null){s.push(root);root=root.left;}}/** @return whether we have a next smallest number */publicbooleanhasNext(){return!s.isEmpty();...
* Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */publicclassSolution{longpre=(long)Integer.MIN_VALUE-1;publicbooleanisValidBST(TreeNoderoot){if(root==null){returntrue;}if(isValid...