Leetcode | Recover Binary Search Tree Two elements of a binary search tree (BST) are swapped by mistake. Recover the tree without changing its structure. Note: A solution using O(n) space is pretty straight forward. Could you devise a constant space solution? 做到这里又有点不知道BST是什么。
题目 题意:给你一个BST,其中任意两个元素被交换过了,让你把交换的元素复原。 题解:BST的中序遍历是个有序的数组,那么两个元素被交换了,我们可以for循环一次找出这两个数字。从小到大遍历,维护一个值max,表示当前遍历元素的最大值。由于两个元素被交换了,所以max一定有一段时间是不变的,直到遇到一个比max大...
https://leetcode.com/problems/recover-binary-search-tree/discuss/32535/No-Fancy-Algorithm-just-Simple-and-Powerful-In-Order-Traversal 描述 解析 解决方法是利用中序遍历找顺序不对的两个点,最后swap一下就好。 因为这中间的错误是两个点进行了交换,所以就是大的跑前面来了,小的跑后面去了。 所以在中序...
e.g. The correct BST is below: 【LeetCode】RecoverBinarySearchTree The inorder traversal is : 1 3 4 6 7 8 10 13 14 Find the place which the order is wrong. Wrong order: 1 3 8 6 7 4 10 13 14 FIND: 8 6 Then we find: 7 4 8, 6 是错误的序列, 但是,7,4也是错误的序列。
下面是leetcode这道题目我的解答。没有使用O(1)空间复杂度,使用了O(n)空间复杂度。 还用到了Java里面 Arrays.sort方法,也需要注意toArray函数的参数。 1. AI检测代码解析 除了这种解法,还有一种,是我之前做的方法,也很好,通过两个数字记录可能出错的位置,很巧妙,在这个后面给出。
leetcode 99. Recover Binary Search Tree Two elements of a binary search tree (BST) are swapped by mistake. Recover the tree without changing its structure. Example 1: Input: [1,3,null,null,2] Output: [3,1,null,null,2] 二叉搜索树,其中两个节点发生了对换,导致不再......
* 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: void recoverTree(TreeNode* root) { ...
Two elements of a binary search tree (BST) are swapped by mistake. Recover the tree without changing its structure. Note: A solution using O(n) space is pretty straight forward. Could you devise a constant space solution? Solution1:In order dfs ...
Recover the tree without changing its structure.Note: A solution using O(n) space is pretty straight forward. Could you devise a constant space solution? 这个题我看到的想法是先把所有element in order走一遍,然后存进O(n) space的array. 然后排序。排序好以后重新建一个BST. ...
Recover Binary Search Tree leetcode java 题目: Two elements of a binary search tree (BST) are swapped by mistake. Recover the tree without changing its structure. Note: A solution using O(n) space is pretty straight forward. Could you devise a constant space solution?