Question

  public void duplicate()
    {
        int repeatation = 0;
        Node current = root;
        Node duplicate = root;
        while (current == null)
        {
            if (duplicate == current || duplicate == current.right  ||  duplicate== current.left)
            {
                Console.WriteLine("node is repeated :" + duplicate);
                repeatation++;



            }

        }
        Console.WriteLine("number of repeatation is :"  + repeatation);

    }

this code is for duplicate elements in binary search tree and how many time a element repeat but its not working properly ,would you tell me whats wrong with this code and i am not sure i code it right or not……

Answer 1

Here’s an approach that might help you with this issue:

1) Get the maximum value in your BST (just go right, right, …, right until you reach a leaf)

2) follow this pseudo code:

for i = 0 to MAX_VALUE do
  currentNode = root;
  while(TRUE)
      if (currentNode.Value == i)
           apprearanceCount++;
      if (i > currentNode.Value)
           currentNode = currentNode.RightNode;
      else 
           currentNode = currentNode.LeftNode;
      if currentNode == NULL then break; // Don't forget to save appearance count