Find the Closest Element in BST
Medium Accuracy: 49.94% Submissions: 19842 Points: 4

Given a BST and an integer. Find the least absolute difference between any node value of the BST and the given integer.

Example 1:

Input:
10
/   \
2    11
/  \
1    5
/  \
3    6
\
4
K = 13
Output: 2
Explanation: K=13. The node that has
value nearest to K is 11. so the answer
is 2


Example 2:

Input:
8
/   \
1     9
\     \
4    10
/
3
K = 9
Output: 0
Explanation: K=9. The node that has
value nearest to K is 9. so the answer
is 0.

minDiff() that takes the root of the BST and an integer K as its input and returns the minimum absolute difference between any node value of the BST and the integer K.

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

Constraints:
1 <= Number of nodes <= 100000