LCA for BST

//ITERATIVE  O(1) SPACE
class Solution {
    public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {

        // Value of p
        int pVal = p.val;

        // Value of q;
        int qVal = q.val;

        // Start from the root node of the tree
        TreeNode node = root;

        // Traverse the tree
        while (node != null) {

            // Value of ancestor/parent node.
            int parentVal = node.val;

            if (pVal > parentVal && qVal > parentVal) {
                // If both p and q are greater than parent
                node = node.right;
            } else if (pVal < parentVal && qVal < parentVal) {
                // If both p and q are lesser than parent
                node = node.left;
            } else {
                // We have found the split point, i.e. the LCA node.
                return node;
            }
        }
        return null;
    }
}

//RECURSIVE O(n) SPACE
class Solution {
    public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {

        // Value of current node or parent node.
        int parentVal = root.val;

        // Value of p
        int pVal = p.val;

        // Value of q;
        int qVal = q.val;

        if (pVal > parentVal && qVal > parentVal) {
            // If both p and q are greater than parent
            return lowestCommonAncestor(root.right, p, q);
        } else if (pVal < parentVal && qVal < parentVal) {
            // If both p and q are lesser than parent
            return lowestCommonAncestor(root.left, p, q);
        } else {
            // We have found the split point, i.e. the LCA node.
            return root;
        }
    }
}