Assignment 1 CSI2120

Assignment 1
CSI2120 Programming Paradigms

Due on February 17th (updated) before 11:00 pm in Virtual Campus
6 marks
There are [10 points] in this assignment. The assignment is worth 6% of your final mark.
All code must be submitted in go files. Screenshots, files in a format of a word editor, pdfs, handwritten
solutions, etc. will not be marked and receive an automatic 0.
Question 1. Structures, Methods and Interfaces [5 points]
A simple program to manage ticket sales for a theatre. In the below definition the type and the variable
names are shown in Courier font.
1. Create a struct Play with the following fields:
 A string for the name of the play,
 A slice of Ticket for the purchased tickets for the play,
 A time.Time for the date when the show starts showStart,
 A time.Time for the date when the show ends showEnd.
2. Create struct Comedy and struct Tragedy with the following field (Note that the
default values are given in brackets) and embed a Play.
 A float32 for the number of laughs per minute (0.2 and 0.0),
 A int32 for the number of deaths in the play (0 and 12),
 In addition, the fields in the embedded structure Play will have different default values
depending on the type.
1. name (Tartuffe, Macbeth)
2. purchased (size 0 for both)
3. showStart (Mar. 3rd at 4:00pm, April 16th at 9:30am)
4. showEnd (Mar. 3rd at 5:20pm, April 16th at 12:30pm)
3. Create an interface Show implemented such that it can be used for struct Comedy and
struct Tragedy defining methods
 getName() (string) returns the name of the show,
 getShowStart() (time.Time) returns the start time of the show,
 getShowEnd() (time.Time) returns the end time of the show,
CSI 2120 page 2
_________________________________________________________________________________________________
 addPurchase(*Ticket)(bool) which adds a ticket to the slice of purchased tickets
and returns true if adding the ticket worked (It is to fail if ticket for the same seat has already
been sold), and
 isNotPurchased(*Ticket)(bool)returns true if a ticket for the same seat is not
already sold.
4. Create the structure Seat with the following fields (Note that the default values are given in
brackets)
 An int32 for the number of the seat (1),
 An int32 for the row of the seat (1), and
 A *Category as variable cat that encodes the category of the seat. (See default values for
Category).
5. Create the structure Category with the following fields (Note that the default values are given
in brackets)
 A literal string for the name of the category where the name can be “Prime”,
“Standard”, “Special” (“Standard”), and
 A float32 for the base price of the category (25.0).
6. Create the structure Ticket with the following fields (Note that the standard go default values
are fine)
 A string holding the customer name,
 A *Seat to the seat s purchased, and
 A *Show to the show show the ticket is for.
7. Create the structure Theatre with the following fields
 An slice of Seat that contains all the seats in the theatre
 A slice of Show that lists all the shows coming up.
8. Implement the following global functions
 NewSeat with an arguments seat number and row number both as int32 and a category as
a *Category
 NewTicket that takes a customer name as string, a pointer to a seat as *Seat and show
as *Show as arguments
 NewTheatre that takes an int32 as input for the number of seats and a slice of Show as
the shows put on by the theatre.
The above functions are factories, i.e., the functions must return a new variable of the type
corresponding to their name by pointer.
CSI 2120 page 3
_________________________________________________________________________________________________
Supply a main routine that constructs a theatre with 25 seats in 5 rows evenly. The seats will have to
be numbered from the front to the back of theatre starting at the front left. There are three categories
of seats where row 1 is considered prime, rows 2 to 4 are standard and row 5 is special. The theatre
will put on one comedy and one tragedy at two different dates of March 3rd, 2020 at 7:30pm to
10:00pm and April 10th, 2020 at 8:00pm to 11:00pm, respectively. The base price of the categories
Prime, Standard and Special are 35, 25 and 15, respectively.
Once your program has initialized all the needed structures, your program has to go in a forever loop
where an agent can sell tickets in a console application for these two plays. The agent is entering the
play and the desired seat. If the seat is already taken but the play is not, the program has to offer an
alternative seat in the same category. If the category is sold out, a seat in an alternative category has
to be offered, first, in a more expensive category and only if not available a less expensive category.
You only need to consider purchases of one ticket at a time.
Please define extra helper functions as needed.
CSI 2120 page 4
_________________________________________________________________________________________________
Question 2. Concurrency [5 points]
Write a program that simulates a Neural Network where each neuron runs concurrently. We use what is
called a multilayer perceptron with 1 hidden layer with an input and output layer. Each neuron calculates
the weighted sum of its input (including an offset) and applies the sigmoid function 𝜎(𝑣) =
1
1+𝑒−𝑣
to its
output. Consider the Figure below for the example of a slice of size 2.
In the above example the equation for the first hidden neuron 𝑍1 = 𝜎(𝛼10 + 𝛼11𝑋1 + 𝑎12𝑋2
). The
equation for the output neuron is 𝑇1 = 𝜎(𝛽10 + 𝛽11𝑍1 + 𝛽12𝑍2 + 𝛽13𝑍3). The inputs 𝑋1 and 𝑋2 simply
pass their value to all hidden layers.
Your program must create exactly he network shown above with the following parameters
𝛼10 = 0.1 𝛼11 = 0.3 𝑎12 = 0.4
𝛼20 = 0.5 𝛼21 = 0.8 𝑎22 = 0.3
𝛼30 = 0.7 𝛼31 = 0.6 𝑎32 = 0.6
𝛽10 = 0.5 𝛽11 = 0.3 𝛽12 = 0.7 𝛽13 = 0.1
You need to design a Go program to calculate the output of the neural network based on input data. The
calculation of each neuron must be done in a go routine; the neuron must therefore wait to have received
the output values (communicated via a channel) from its input neurons before calculating the value of its
output.
Your program must apply the neural network to a series of input values in a loop and calculate the
network output for the input. These input values are 𝑋1,𝑘 = sin 2𝜋(𝑘−1)
𝑁
and 𝑋2,𝑘 = cos
2𝜋(𝑘−1)
𝑁
where
𝑘 = 1 … 𝑁 is the value of the current loop variable. You must make sure that the calculation at iteration
k-1 has been completed before calculating the output value at iteration k. The output value of the
𝑋1
𝑍1
𝑇1
𝑍2 𝑍3
𝑋2
Hidden Layer
Output Layer
Input Layer 1
1
CSI 2120 page 5
_________________________________________________________________________________________________
network is communicated to the main program via a channel. The main program will have to print the
value to console. Your Go program must let the user enter the number of inputs 𝑁.