Assignment 2 Chasing Alice

CPSC 231: Introduction to Computer Science for Computer Science Majors I
Assignment 2

Assignment Objectives:
This is an individual assignment. You must submit your own work. This assignment has three goals:
1. Analyzing requirements and developing a solution
2. Reviewing python constructs including., if, if-else, if-elif-else, loops, and functions
3. Practicing basic python programming
Start the assignment early and avoid procrastination.
Chasing Alice
For this assignment, you develop a turn-based game where you control a blue turtle, Alex, to chase and catch
a red turtle, Alice. Create a canvas (also known as screen) of size 500 x 500. Alex must appear at the middle of
the canvas. Alice appears at a random location inside the canvas.
In each turn, Alice can move either forward by 20 pixels or she can change her direction randomly to left or
right by 90 degrees. 2/3 of Alice’s movements should be forward movements and 1/3 should be the random
direction changing left or right, see figure 1 below.
Alex moves as directed by the player using the keyboard. In each turn, the buttons w, a, s, and d lead Alex to
move forward for 30 pixels, turn left for 45 degrees, back for 30 pixels, and right for 45 degrees, respectively.
If Alex or Alice cross the canvas’s boundaries, they should reappear at a random1
location on the canvas. The
game statistic needs to be provided on the screen as shown in the sample. The game ends if Alex comes within
30 pixels of Alice in any direction. See figure 2 to get an idea of how the game will look like.

1 To learn how to generate random numbers in python, look at: https://docs.python.org/3/library/random.html
Alice movement
Alex Movement
20 Pixels
90 Degree
90 Degree
45
Degree
30 Pixels
Figure 1: Alice and Alex movements
Figure 2: Samples of how the game will look like
Marking:
Category 5 Points 4 Points 3 Points 2 Point 1 Point 0 point
Setup Turtles are setup
correctly (colors,
shapes,
locations)
Turtles are not
setup correctly
Alice
movement
Alice moves
correctly (distance,
angles, 2/3 fwd.,
1/3 changing dir.)
Alice moves
partially correctly
Alice does not
move correctly
Alex
movement
Arrow keys
properly transfer to
Alex movement
Arrow keys
partially transfer
to Alex
movement
Arrow keys does
not properly
transfer to Alex
movement
Modularity There is
one
function
for each
distinct
task
Small
part of
code is
not in
function
Most of the
code is
developed
inside functions
Half of the code are
in functions
Or functions
contain unrelated
codes
Limited use of
functions
No proper use
of functions
Detection
of catching
Correct detection of
Alice catching
Some reasonable
codes for the
catching function
Alice catch is
not detected
Detection
& handling
of turtles
leaving the
canvas
Turtles leaving the
canvas is detected
& handled
Turtles leaving
the canvas is
partially detected
or partially
handled
Turtles leaving
the canvas is
not detected
Showing
statistics
The statistic is
shown correctly
The statistic is
shown partially
correctly
Statistics are not
shown
Using
constants
and local
variables
Code contains local
variables and wellnamed constants
Without any magic
number or global
variables
Code contains
magic numbers
or global
variables
Comments
and
variable
naming
Consistence
variable naming,
student information
at the top of the
code + Code is
commented well,
Program name is
correct
Inadequate
comments or
inconsistent
variable naming
or variable
names are not
meaningful
No comments
or inconsistent
variable naming
or variable
names are not
meaningful,
program name
is not correct
Total 20
Submission requirements
In order to receive a complete grade no global variable or codes outside functions should be in your program.
Create a main function and control the program by calling other functions through main. The program starts
with calling main() only. Use constants instead of magic numbers. Follow variable name conventions all
through your code and be consistence. Use white lines to separate blocks of codes.
Name your program ChasingAlice.py then submit it to the D2L Assignment 2 dropbox by the deadline stated at
the top of this document.
Collaboration, Plagiarism, and Cheating
This is an individual assignment and all work that you submit must be your own work. We encourage you to
discuss this assignment with other students in the course and discourage you from sharing solutions and code
with one another. Sharing solutions and code is a form of plagiarism.
We use automated procedures to detect plagiarism in assignment submissions. Any student who copies all or
part of an assignment that belongs to another student or other sources will be reported to the Dean. The
Dean enforces penalties, which may include failing the course and expulsion from the faculty and the
university. Please refer to Plagiarism/Cheating/Other Academic Misconduct in the university calendar or the
university website on plagiarism for more information.