Given a binary search tree and a node in it, find the in-order successor of that node in the BST. Note: If the given node has no in-order successor in the tree, return null. 这道题让我们求二叉搜索树的某个节点的中序后继节点,那么我们根据BST的性质知道其中序遍历的结果是有序的, 是我最先用的方法是用迭代的中序遍历方法,然后用…

Given a binary search tree and a node in it, find the in-order successor of that node in the BST. The successor of a node p is the node with the smallest key greater than p.val. Example 1: Input: root = [2,1,3], p = 1 Output: 2 Explanation: 1's in-or…

Given a binary search tree and a node in it, find the in-order successor of that node in the BST. The successor of a node p is the node with the smallest key greater than p.val. You will have direct access to the node but not to the root of the tree.…

Given a binary search tree and a node in it, find the in-order successor of that node in the BST. The successor of a node p is the node with the smallest key greater than p.val. Example 1: Input: root = [2,1,3], p = 1 Output: 2 Explanation: 1's in-or…

Leetcode:1305. 两棵二叉搜索树中的所有元素 Leetcode:1305. 两棵二叉搜索树中的所有元素 思路 BST树中序历遍有序. 利用双指针法可以在\(O(n)\)的复杂度内完成排序. 基于上述两个点,可以很简单的做出这道题. 先中序历遍得到两个有序的数列. 利用双指针法,只需历遍一次就可以得到升序的答案. Talk is cheap . Show me the code . /** * Definition for a binary tree node. * struct Tr…

Given a binary search tree, write a function kthSmallest to find the kth smallest element in it. Note: You may assume k is always valid, 1 ≤ k ≤ BST's total elements. Follow up: What if the BST is modified (insert/delete operations) often and you nee…

Given a binary search tree, write a function kthSmallest to find the kth smallest element in it. Note: You may assume k is always valid, 1 ≤ k ≤ BST's total elements. Example 1: Input: root = [3,1,4,null,2], k = 1 3 / \ 1 4 \   2 Output: 1 Example 2:…

给定一个二叉搜索树,编写一个函数kthSmallest来查找其中第k个最小的元素. 注意:你可以假设k总是有效的,1≤ k ≤二叉搜索树元素个数. 进阶:如果经常修改二叉搜索树(插入/删除操作)并且你需要频繁地找到第k小值呢? 你将如何优化kthSmallest函数? 详见:https://leetcode.com/problems/kth-smallest-element-in-a-bst/description/ Java实现: /** * Definition for a binary t…

1.非递归解法 /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: int kthSmallest(TreeNode* root, int k) { if(r…

［抄题］: Given a binary search tree with non-negative values, find the minimum absolute difference between values of any two nodes. Example: Input: 1 \ 3 / 2 Output: 1 Explanation: The minimum absolute difference is 1, which is the difference between 2…