# Minimum Absolute Difference in BST

## Question

Given a binary search tree with non-negative values, find the minimum absolute difference between values of any two nodes.

Example:

Input:

 1
\
3
/
2

Output: 1

Explanation: The minimum absolute difference is 1, which is the difference between 2 and 1 (or between 2 and 3).

Note: There are at least two nodes in this BST.