Recursive Algorithm to Cut a Binary Search Tree (Remove Nodes Not In Range)

# class Tree:
#     def __init__(self, val, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def cutBinarySearchTree(self, root, lo, hi):
        if root is None:
            return root
        if root.val < lo:
            return self.solve(root.right, lo, hi)
        if root.val > hi:
            return self.solve(root.left, lo, hi)
        root.left = self.solve(root.left, lo, hi)
        root.right = self.solve(root.right, lo, hi)
        return root

/**
 * class Tree {
 *     public:
 *         int val;
 *         Tree *left;
 *         Tree *right;
 * };
 */
Tree* cutBinarySearchTree(Tree* root, int lo, int hi) {
    if (!root) return root;
    if (root->val < lo) return cutBinarySearchTree(root->right, lo, hi);
    if (root->val > hi) return cutBinarySearchTree(root->left, lo, hi);
    root->left = cutBinarySearchTree(root->left, lo, hi);
    root->right = cutBinarySearchTree(root->right, lo, hi);
    return root;
}