//Given a binary search tree and the lowest and highest boundaries as L and R, trim the

//tree so that all its elements lies in [L, R] (R >= L). You might need to change the root

//of the tree, so the result should return the new root of the trimmed binary search tree.

/**

* Definition for a binary tree node.

* public class TreeNode {

* int val;

* TreeNode left;

* TreeNode right;

* TreeNode(int x) { val = x; }

* }

*/

class TrimABinarySearchTree {

public TreeNode trimBST(TreeNode root, int L, int R) {

if(root == null) {

return root;

}

if(root.val < L) {

return trimBST(root.right, L, R);

}

if(root.val > R) {

return trimBST(root.left, L, R);

}

root.left = trimBST(root.left, L, R);

root.right = trimBST(root.right, L, R);

return root;

}

}