Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
I know that deleting a node from a heap is O(log n) that occures at the root. And I also know that deleting an arbitrary node in a heap in one of the heap tree problems and is O(n).
Is there any algorithm that reduces the running time of deleting the Ith node from a maxheap to O(log n) where I is ranging from 1 to N?
The expensive part of deleting an arbitrary node from a heap isn’t in the deleting, but in finding the node to delete. Actually deleting the node is O(log n). But first you have to do a sequential scan of the underlying data store in order to find the node. That’s the O(n) part.
The only way to speed this up is to keep a second data structure like a dictionary or hash map or similar that can quickly tell you where the item is in the backing store. Then you have an O(1) lookup in the dictionary, an O(1) removal from the dictionary, and an O(log n) removal from the heap.