/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
class Solution {
    public List<TreeNode> delNodes(TreeNode root, int[] to_delete) {
        List<TreeNode> ans1 = new ArrayList<TreeNode>();
        if (to_delete.length==0)
        {
            ans1.add(root);
            return ans1;
        }
        HashSet<Integer> set = new HashSet<Integer>();
        for(int e:to_delete)
            set.add(e);
        ArrayList<TreeNode> ans = delNodes(root, set);
        if(!set.contains(root.val))
            ans.add(root);
        return ans;


    }
    public ArrayList<TreeNode> delNodes(TreeNode root, HashSet<Integer> set)
    {

        ArrayList<TreeNode> ans = new ArrayList<TreeNode>();
        if(root==null)
            return null;
        TreeNode left=root.left;
        TreeNode right=root.right;
        if (set.contains(root.val))
        {
            root=null;
            if(left!=null&&!set.contains(left.val))
                ans.add(left);
            if(right!=null&&!set.contains(right.val))
                ans.add(right);
        }
        if(left!=null)
        ans.addAll(delNodes(left, set));
        if(right!=null)
        ans.addAll(delNodes(right, set));
        return ans;
    }
}