[Solved] 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.

Question

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:

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

Example 2:

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

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

Python Solution

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right

def inorder(root,l):
    if root==None:return
    inorder(root.left,l)
    l.append(root.val)
    inorder(root.right,l)

class Solution:
    def findTarget(self, root: TreeNode, k: int) -> bool:
        l = []
        inorder(root,l)
        i=0
        j=len(l)-1
        while i<j:
            if l[i]+l[j]==k:return True
            elif l[i]+l[j]<k:i+=1
            else:j-=1
        return False
Abhishek Sharma
Abhishek Sharma

Started my Data Science journey in my 2nd year of college and since then continuously into it because of the magical powers of ML and continuously doing projects in almost every domain of AI like ML, DL, CV, NLP.

Articles: 514

Leave a Reply

Your email address will not be published. Required fields are marked *