Lynn Trickey's Stacks, Queues and Job Simulation

[ltrickey]

Stacks and Queues

Thanks for doing some brain yoga. You are now submitting this assignment!

Comprehension Questions

Question	Answer
What is an ADT?	ADT is a type (class?) of data types. It stands for Abstract Data Types. Each of these different types of Data also have specific rules about how you can store information and interact with or access that information.
Describe a Stack	A stack is a data type with last in first out logic. You enter pieces of data into the stack and can only access or remove the lass piece entered and stored. You must remove that piece of data to access any other data in the stack which is "beneath" it.
What are the 5 methods in Stack and what does each do?	push adds data. pop removes the last piece of data added. empty? checks if the stack is empty. top reads/accesses the very last piece of data entered but does not remove it. size accesses how many things are stored in the stack.
Describe a Queue	A queue is a data type where data is stored and accessed with first in first out logic, meaning the only piece of data that can be accessed is the first thing entered. You must remove this first object to then access the next object entered, etc.
What are the 5 methods in Queue and what does each do?	enqueue adds a piece of data to the queue, dequeue removes the first thing added (or the earliest thing added if that first piece has been removed). Empty? checks if the queue is empty. Front will access the first or earliest piece of data and read/return it but won't remove it. Size will tell you how many things are stored in the queue.
What is the difference between implementing something and using something?	implementing is creating a class or method, meaning writing how the behavior will work, what elements go into it. Using is actually calling an instance of that class, or calling that method on an object.

OPTIONAL JobSimulation

Question	Answer
Did you include a sample run of your code as a comment?	Pasting it here:

Before the simulation starts
Employed: ["Worker #1", "Worker #2", "Worker #3", "Worker #4", "Worker #5", "Worker #6"]
Waitlist: ["Worker #7", "Worker #8", "Worker #9", "Worker #10"]

-------Cycle 1-------
Employed: ["Worker #1", "Worker #2", "Worker #3", "Worker #4", "Worker #7", "Worker #8"]
Waitlist: ["Worker #9", "Worker #10", "Worker #6", "Worker #5"]

-------Cycle 2-------
Employed: ["Worker #1", "Worker #2", "Worker #3", "Worker #9", "Worker #10", "Worker #6"]
Waitlist: ["Worker #5", "Worker #8", "Worker #7", "Worker #4"]

-------Cycle 3-------
Employed: ["Worker #1", "Worker #2", "Worker #3", "Worker #9", "Worker #10", "Worker #5"]
Waitlist: ["Worker #8", "Worker #7", "Worker #4", "Worker #6"]

-------Cycle 4-------
Employed: ["Worker #1", "Worker #2", "Worker #3", "Worker #8", "Worker #7", "Worker #4"]
Waitlist: ["Worker #6", "Worker #5", "Worker #10", "Worker #9"] |

[sudocrystal]

You shouldn't change the variables that I put here. If this is the spec that's given to you then these are the names of the variables that will be expected in other places, so if you change it here, other programs expecting these names won't work properly. Also no adding variables (waitlist) or removing variables (roll)

[sudocrystal]

It's fine to break out this task into its own method - but if doing so, it should be a private method that is used within the class, but not available outside the class (which is what making it private does)

[sudocrystal]

It's fine to make this variable and use it. But if doing so, it should be a local variable, not an instance variable, as it won't be (shouldn't be) used in other methods as well.

[sudocrystal]

Another solution that's a little easier to read is:

jobs_available.times do |i|
  @employed.push("Worker \##{i+1}")
end

[sudocrystal]

same note about style of loop and using |i| here. Though this one is a little trickier to make sure that the numbering would start at 7, in this case, instead of 1. But it can be done with a little math.

[sudocrystal]

This should be @roll as it's the variable that I indicated in the atrr_reader

[sudocrystal]

Stacks and Queues

What We're Looking For

Feature	Feedback
Implementation of Stack looks complete	yes
Implementation of Queue looks complete	yes

OPTIONAL JobSimulation

Extension	Feedback
Does the code solve the problem to specification?	no
Is the code easy to follow?	yes
Does the output look good?	yes
Were provided variables and methods used appropriately and not altered in name or definition?	no
Were any new variables and/or methods made private to the class?	no

Overall this looks good! I just left some notes on some areas where you didn't exactly follow the skeleton that I provided and ended up altering the functionality of JobSimulation as a result.