Lab Assignment #5 – Using Trees and Priority Queues
Due Date:Friday, Week 10
Purpose:The purpose of this Lab assignment is to:
Design algorithms that describe operations on ADT Trees and priority queues.
Implement and test appropriate methods in Java or Python
References:Read the course’s text chapter 8, 9 and the lecture slides. This material provides the necessary information that you need to complete the exercises.
Be sure to read the following general instructions carefully:
- This assignment must be completed individually by all the students.
- You will have to demonstrate your solution in a scheduled lab session and upload the solution on eCentennial through the assignment link.
Exercise 1
Design the algorithm and method for one of the following operations for a binary tree T:
preorderNext(p): Return the position visited after p in a preorder traversal of T (or null if p is the last node visited).
inorderNext(p): Return the position visited after p in an inorder traversal of T (or null if p is the last node visited).
postorderNext(p): Return the position visited after p in a postorder traversal of T (or null if p is the last node visited).
Write a Java/Python to test your solution.
What are the worst-case running times of your algorithms?
Exercise 2
Give an efficient algorithm that computes and prints, for every position p of a tree T, the element of p followed by the height of p’s subtree. Write a Java/Python to test your solution.
Hint: Use a postorder traversal to find the height of each subtree. The height for a subtree at p will be 0 if p is a leaf and otherwise one more than the height of the max child. Print out the element at p and its computed height during the postorder visit.
(3 marks)
Exercise 3
Give an alternative implementation of the HeapPriorityQueue’s upheap method that uses recursion (and no loop). Hint: Do a single upward swap and recur (if necessary).
Evaluation:
Correct implementation of requirements:
Correct ADT data structure algorithm
Correct Java or Python implementation
Explanation of algorithm when asked 90%
You must name your Eclipse project according to the following rule:
YourFullname_COMP254Labnumber_Exercisenumber.
Example: JohnSmith_ COMP254Lab5_Ex1
Submission rules:
Submit your modules as zip files that are named according to the following rule:
YourFullname_ COMP254Labnumber_Exercisenumber.zip
Example: JohnSmith_ COMP254Lab5_Ex1.zip
Use 7-zip to compress files (https://www.7-zip.org/download.html).