Lowest Common Ancestor of a Binary Search Tree

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

According to the definition of LCA on Wikipedia: “The lowest common ancestor is defined between two nodes v and w as the lowest node in T that has both v and w as descendants (where we allow a node to be a descendant of itself).”

        _______6______
       /              \
    ___2__          ___8__
   /      \        /      \
   0      _4       7       9
         /  \
         3   5
For example, the lowest common ancestor (LCA) of nodes 2 and 8 is 6. Another example is LCA of nodes 2 and 4 is 2, since a node can be a descendant of itself according to the LCA definition.

Code

public class Solution {
    public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {
        //if root val smaller than one and bigger than other one, return root
        //if root val smaller than both, call same function on root.right
        //if root val bigger than both, call same function on root.left

        if (root==p || root==q || (root.val-p.val)*(root.val-q.val) < 0) return root;

        else if (root.val < p.val) return lowestCommonAncestor(root.right, p, q);
        else return lowestCommonAncestor(root.left, p, q);

    }
}