Description
Introduction to CS
1. Shuffling cards
In lecture 4-2 we presented a shuffle algorithm. We applied the algorithm to a deck of cards, implemented as
an array of String values. The algorithm performed “in place” shuffling, meaning that the original array is
mutated. As a result, following a shuffle, there is no way to go back to, or reconstruct, the original array.
Implement a version of the shuffle algorithm that creates a new array which is the shuffled version of the
original array. In order to so, modify the code of the supplied Deck class. In particular, the shuffle function
should create, and return, a new array representing a random shuffle of the input deck. The original array
must be kept unchanged.
Running the modified Deck program should print the original deck, then the shuffled deck, and finally the
original deck again. For example:
♠2 ♦2 ♥2 ♣2 ♠3 ♦3 ♥3 ♣3 ♠4 …
♠3 ♠2 ♦3 ♠4 ♥2 ♣2 ♣3 ♦2 ♥3 …
♠2 ♦2 ♥2 ♣2 ♠3 ♦3 ♥3 ♣3 ♠4 …
This a relatively simple exercise, since most of the necessary code is given. However, it provides a good
practice for working on the remaining exercises in this homework.
2. Array operations
Given an array of int values and an integer m, we wish to go through all the subarrays of size m, and find the
subarray that has the largest sum of array values. This operation is featured, among other operations, in the
supplied ArrayOps class.
Complete the supplied ArrayOps class by implementing the three functions whose code is missing. If you’ll
complete your work successfully, the last test function should print “success: true” instead of “success:
false”.
3. String operations
Complete the given StringOps class. You have to write five functions. We recommend implementing and
testing them in the order in which they appear in the class.
Submission
Before submitting your solution, inspect your code and make sure that it is written according to our
Java Coding Style Guidelines. Also, make sure that each program starts with the program header
described in the Homework Submission Guidelines. Both documents can be found in the Moodle
site, it is your responsibility to read them. Any deviations from these guidelines will result in points
penalty. Submit the following five files only:
➢ Deck.java
➢ ArrayOps.java
➢ StringOps.java
Deadline: Submit Homework 3 no later than December 2, 23:55. You are welcome to submit earlier.
