// Lowest Common Ancestor of a BST — MEDIUM

// Category: tree

Given a binary search tree (BST), find the lowest common ancestor (LCA) node of two given nodes in the BST.

According to the definition of LCA: 'The lowest common ancestor is defined between two nodes `p` and `q` as the lowest node in `T` that has both `p` and `q` as descendants (where we allow a node to be a descendant of itself).'

**Insight:** In a BST, if both `p` and `q` are smaller than `root`, the LCA is in the left subtree. If both are larger, it's in the right subtree. Otherwise, `root` is the LCA.

Example: root = [6,2,8,0,4,7,9], p = 2, q = 8

Output: 6