Recover Binary Search Tree
You are given the root of a binary search tree (BST), where the values of exactly two nodes of the tree were swapped by mistake. Recover the tree without changing its structure.
Example 1:
Input: root = [1,3,null,null,2]
Output: [3,1,null,null,2]Example 2:
Input: root = [2,3,1]
Output: [2,1,3]Constraints:
2 <= The number of nodes in the tree <= 1000.-(2^31) <= Node.val <= ((2^31)-1)
Follow up: A solution using O(n) space is pretty straight-forward. Could you devise a constant O(1) space solution?