Description
1 Programming Assignment
The assignment is to create a binary search tree (BST) and test whether the tree is a valid AVL
tree.
A Java template has been provided containing two classes: AVL BST and BST. Your task is to
write the body of the createBST and the checkAVL functions. You have complete freedom in
designing the BST class, and you can add any helper methods you need in the AVL BST class. You
may introduce more private classes, but they have to be declared in the same file. Your code is not
required to check for incorrectly formed input data.
You must use the provided Java template as the basis of your submission. You may not change
the name, return type or parameters of any of the given functions. The main function in the
template contains code to help you test your implementation. You may modify the main function,
since the main function will be deleted before marking begins. You can submit ONLY the file named
“AVL BST.java”. If you submit multiple files or change the name of the class or the functions (even
lowercase to uppercase or vice versa), your submission may generate compilation error during the
automated testing and you will be graded accordingly.
2 Examples
The samples below show the correct output for various test inputs.
Input Array checkAVL() output
82, 85, 153, 195, 124, 66, 200, 193, 185, 243, 73, 153, 76 false
5, 3, 7, 1 true
5, 1, 98, 100, −3, −5, 55, 3, 56, 50 true
297, 619, 279, 458, 324, 122, 505, 549, 83, 186, 131, 71 false
78 true
3 Evaluation Criteria
The programming assignment will be marked out of 50, based on a combination of automated
testing and human inspection. You may safely assume that the maximum size of an input array
will be 10000.
1
The mark for each submission will be based on both the asymptotic worst case running time
and the ability of the algorithm to handle inputs of different sizes. The table below shows the
expectations associated with different scores.
Score Description
0 – 10 Submission does not compile or does not conform to the provided
template.
11 – 25 The submission is substantially inaccurate on the tested inputs
(fails more than 50% of the test cases).
26 – 30 Any of the two functions createBST and checkAVL takes more
than O(n log n) time.
31 – 50 Each of the two functions takes O(n log n) time. The numbers
would vary based on how many test cases your algorithm gives
correct answer to.
To be properly tested, every submission must compile correctly as submitted, and must be based
on the provided template. If your submission does not compile for any reason (even trivial mistakes
like typos), or was not based on the template, it will receive at most 10 out of 50. The best way to
make sure your submission is correct is to download it from conneX after submitting and test it.
You are not permitted to revise your submission after the due date, and late submissions will not
be accepted, so you should ensure that you have submitted the correct version of your code before
the due date. conneX will allow you to change your submission before the due date if you notice
a mistake. After submitting your assignment, conneX will automatically send you a confirmation
email. If you do not receive such an email, your submission was not received. If you have problems
with the submission process, send an email to the instructor before the due date
