new_contents: """Leetcode 1110. Delete Nodes And Return Forest
  Medium
  
  URL: https://leetcode.com/problems/delete-nodes-and-return-forest/
  
  Given the root of a binary tree, each node in the tree has a distinct value.
  
  After deleting all nodes with a value in to_delete, we are left with a forest
  (a disjoint union of trees).
  
  Return the roots of the trees in the remaining forest.  You may return the
  result in any order.
  
  Example 1:
  Input: root = [1,2,3,4,5,6,7], to_delete = [3,5]
  Output: [[1,2,null,4],[6],[7]]
   
  Constraints:
  - The number of nodes in the given tree is at most 1000.
  - Each node has a distinct value between 1 and 1000.
  - to_delete.length <= 1000
  - to_delete contains distinct values between 1 and 1000.
  """
  
  # Definition for a binary tree node.
  class TreeNode(object):
      def __init__(self, val):
          self.val = val
          self.left = None
          self.right = None
  
  
  class Solution(object):
      def delNodes(self, root, to_delete):
          """
          :type root: TreeNode
          :type to_delete: List[int]
          :rtype: List[TreeNode]
          """
          pass
  
  
  def main():
      pass
  
  
  if __name__ == '__main__':
      main()
  
subject: Add lc1110_delete_nodes_and_return_forest.py