也可以使用递归的方式: classSolution {public:intkthSmallest(TreeNode* root,intk) {returnSmallest(root,k); }intSmallest(TreeNode* root,int&k){if(root ==NULL)return-1;intnum = Smallest(root->left,k);if(k ==0)returnnum;if(--k ==0)returnroot->val;returnSmallest(root->right,k); } ...
Given a binary search tree, write a functionkthSmallestto find thekth 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 need to find the kth smallest frequen...
kthSmallestto 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 need to find the kth smallest frequently? How would you optimize the kthSmallest...
Given a binary search tree, write a function kthSmallest to find the kth smallest element in it. 求一个二叉搜索树的第k小值。 题目链接:https://leetcode.com/problems/kth-smallest-element-in-a-bst/ 先来看下二叉搜索树的性质,对于任意一个非叶子节点,它的左子树中所有的值必定小于这个节点的val,...
Given a binary search tree, write a functionkthSmallestto 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 need to find the kth smallest frequ...
Leetcode 第230题:Kth Smallest Element in a BST--二叉搜索树中第K小的元素(C++、Python) 题目地址:Kth Smallest Element in a BST 题目简介: 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。 说明:你可以假设 k 总是有效的,1 ≤ k ≤ 二叉搜索树元素个数。 示例 1: ...
publicclassSolution{publicintkthSmallest(int[][]matrix,int k){if(matrix.length==0||matrix[0].length==0)return0;int[]index=newint[matrix.length];int pos=0;int small=matrix[matrix.length-1][matrix[0].length-1];;for(;k>0;k--){small=matrix[matrix.length-1][matrix[0].length-1];fo...
总体上,我们只需要增加两个变量num和res。num记录中序遍历已经输出的元素个数,当num == k的时候,我们只需要将当前元素保存到res中,然后返回即可。 下边分享下三种遍历方式的解法,供参考。 递归法。 intnum=0;intres;publicintkthSmallest(TreeNoderoot,intk){inorderTraversal(root,k);returnres;}privatevoidin...
Follow up:What if the BST is modified (insert/delete operations) often and you need to find the kth smallest frequently? How would you optimize the kthSmallest routine? 思路: 由于bst的性质,所以bst的中序遍历,就是把bst从小到大输出,这样就能很容易找到第k小的数。
这道题让我们求链表中倒数第k个元素,LeetCode中相类似的题目有Kth Largest Element in an Array 数组中第k大的数字和Kth Smallest Element in a BST 二叉搜索树中的第K小的元素。但那两道题和这题又不一样,首先这道题是要在链表中操作,链表的特点就是不能通过下标来直接访问元素,而且要知道链表长度的话只...