Question $4(20$ points$)$:

Purpose: To build a program and test it$,$ without starting with a design document. To get warmed up with

Python, in case you are using it for the first time.

Degree of Difficulty: Moderate. Don$$t leave this to the last minute. This task involves an unfamiliar prob$-$

lem, but the program itself is not more difficult than anything you$$ve done in CMPT $141.$

References: You may wish to review the following chapters:

$$ Lists: CMPT $145$ Readings: Chapter $2.$

$$ File I$/$O Review: CMPT $141$ Readings: Chapter $12$

Restrictions: This question is homework assigned to students and will be graded. This question shall not

be distributed to any person except by the instructors of CMPT $145.$ Solutions will be made available

to students registered in CMPT $145$ after the due date. There is no educational or pedagogical reason

for tutors or experts outside the CMPT $145$ instructional team to provide solutions to this question

to a student registered in the course. Students who solicit such solutions are committing an act of

Academic Misconduct, according to the University of Saskatchewan Policy on Academic Misconduct.

Note: a$1$q$5$ asks about your work on a$1$q$4$

Keep track of how long you spend working on this question, including time spent reading the ques$-$

tion, reviewing notes and the course readings, implementing the solution, testing, and preparing to

submit. Also keep track of how many times you experienced unscheduled interruptions, delays, or

distractions during your work; include things like social media, phone calls, texting, but not such

things as breaking for a meal, exercise, commuting to or from the university. In a$1$q$5$ you will be

asked to summarize the time you spend working on a$1$q$4,$ and your answer will be more helpful to

you if you have more precise records. Maybe go and read Q$5$ before you start Q$4?$

The Torus Square

The following description considers the manipulation of a $3\backslash$times $3$ array of integers, which can be considered

a kind of simple game. The description will start by describing the rules of the game, and then you$$ll be

told what your task will be$.$ It is highly unlikely that you will discover anything sensible on the internet about

this game. It was invented by one of your instructors.

Consider an $3\backslash$times $3$ array of integers $\{0,,8\}$ such as:

$012$

$345$

$678$

This is a kind of a puzzle, where we allow rows to be shifted left or right, and columns to be shifted up or

down. We will call these actions unit rotations, for reasons that will be clarified immediately.

A unit rotation is simply a shift of all the elements of a row $($or column$)$ by one position. For example, we

can rotate the top row of the previous example one position to the right to get the following:

$201$

$345$

$678$

Notice that the integer $2$ that was on the end of the row moved to the front after the rotation to the right.

Because the number $2$ moved to the front of the row, we call it a rotation. Similarly, we can rotate the

bottom row one position to the left to get the following:

Page $8$