讲解program编程、辅导Java程序

日期：2021-03-28 06:46

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 asked90%

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).