problem653

README

< Previous 　　　　　　　　　　　　　　　　 Next >

653. Two Sum IV - Input is a BST (Easy)

Given the root of a Binary Search Tree and a target number k, return true if there exist two elements in the BST such that their sum is equal to the given target.

 

Example 1:

Input: root = [5,3,6,2,4,null,7], k = 9
Output: true

Example 2:

Input: root = [5,3,6,2,4,null,7], k = 28
Output: false

Example 3:

Input: root = [2,1,3], k = 4
Output: true

Example 4:

Input: root = [2,1,3], k = 1
Output: false

Example 5:

Input: root = [2,1,3], k = 3
Output: true

 

Constraints:

• The number of nodes in the tree is in the range [1, 104].
• -104 <= Node.val <= 104
• root is guaranteed to be a valid binary search tree.
• -105 <= k <= 105

Related Topics

[Tree] [Depth-First Search] [Breadth-First Search] [Binary Search Tree] [Hash Table] [Two Pointers] [Binary Tree]

Similar Questions

1. Two Sum (Easy)
2. Two Sum II - Input array is sorted (Easy)
3. Two Sum III - Data structure design (Easy)
4. Two Sum BSTs (Medium)