root of a Binary Search Tree and a target number
true if there exist two elements in the BST such that their sum is equal to the given target.
Input: root = [5,3,6,2,4,null,7], k = 9
Input: root = [5,3,6,2,4,null,7], k = 28
Input: root = [2,1,3], k = 4
Input: root = [2,1,3], k = 1
Input: root = [2,1,3], k = 3
- The number of nodes in the tree is in the range
-104 <= Node.val <= 104
rootis guaranteed to be a valid binary search tree.
-105 <= k <= 105
Time complexity: O(N), where N represents the number of nodes in BST.
Space complexity: O(N)