Find a pair with given target in BST
Medium Accuracy: 47.17% Submissions: 18324 Points: 4

Given a Binary Search Tree and a target sum. Check whether there's a pair of Nodes in the BST with value summing up to the target sum.

Example 1:

Input:
2
/   \
1     3
sum = 5
Output: 1


Example 2:

Input:
6
/
5
/
3
/  \
1    4
sum = 2
Output: 0


isPairPresent() that takes a root node and a target value as a parameter and returns 1 if there's a pair of Nodes in the BST with values summing up to the target sum, else returns 0.

Expected Time Complexity: O(N).
Expected Auxiliary Space: O(Height of the BST).

Constraints:
1<=Number of Nodes<=100000
1<=K<=1000005

Note: The Input/Output format and Example are given are used for the system's internal purpose, and should be used by a user for Expected Output only. As it is a function problem, hence a user should not read any input from the stdin/console. The task is to complete the function specified, and not to write the full code.