Programming C, C++, Java, PHP, Ruby, Turing, VB
Computer Science Canada 
Programming C, C++, Java, PHP, Ruby, Turing, VB  

Username:   Password: 
 RegisterRegister   
 Are YOU ready for Waterloo CS?
Index -> Java
View previous topic Printable versionDownload TopicSubscribe to this topicPrivate MessagesRefresh page View next topic
Author Message
Martin




PostPosted: Fri Aug 20, 2004 4:24 pm   Post subject: Are YOU ready for Waterloo CS?

http://www.cs.uwaterloo.ca/undergrad/admissions/placement/cs134.shtml

This is the test to see if you are ready for CS 134 (the most advanced of the three first year choices for computer science) at the University of Waterloo.

Note: don't email it to the guys unless you actually are attending the university Razz.
Sponsor
Sponsor
Sponsor
sponsor
Dan




PostPosted: Fri Aug 20, 2004 7:11 pm   Post subject: (No subject)

dose not seem that hard to me, i think i had a question alot like that on my grade 12 compsci exame that was on java.
Computer Science Canada Help with programming in C, C++, Java, PHP, Ruby, Turing, VB and more!
wtd




PostPosted: Fri Aug 20, 2004 7:35 pm   Post subject: (No subject)

It does seem pretty easy.
Dan




PostPosted: Fri Aug 20, 2004 7:50 pm   Post subject: (No subject)

Well i guse they do not expceted you to know everything, alot of poleop could have had no compsci corses during high school and/or not progaming excpicen at all. So that whould probly be a good way to weed out any one that has no progaming excpricne from going in to the highested 1st year level right away.
Computer Science Canada Help with programming in C, C++, Java, PHP, Ruby, Turing, VB and more!
wtd




PostPosted: Fri Aug 20, 2004 8:00 pm   Post subject: (No subject)

And, I suppose, to figure out which people are willing to take the time to figure it out, if they didn't already know.

Would it be wrong to post a solution in another language? Smile

I keep hacking stuff together to work my mind around the baroqe syntax of O'Caml.
Martin




PostPosted: Fri Aug 20, 2004 10:51 pm   Post subject: (No subject)

Post it if you want. It's not a test or anything, and anyone at this point who's in CS 134 is stuck in CS 134. Also, Dan, it's required that you have ICS 3M to get into this course (and a teacher recommendation...a joke to get).
wtd




PostPosted: Fri Aug 20, 2004 11:30 pm   Post subject: (No subject)

The module:

code:
module RealEstate =
        struct
                let sum_list = List.fold_left (fun a b -> a +. b) 0.
       
                class agent name =
                        object(self)
                                val mutable commissions = []
                               
                                method get_name = name
                                method name_nil = name = ""
                               
                                method add_commission amount = 
                                        commissions <- amount :: commissions
                                       
                                method total_commissions = sum_list commissions
                        end
                       
                exception No_listing_agent
                       
                class basic_property address init_asking_price =
                        object(self)
                                val mutable asking_price = init_asking_price
                                val mutable selling_price = 0
                                val mutable listing_agent = ref (new agent "")
                                val mutable selling_agent = ref (new agent "")
                                val mutable sold = false
                               
                                method private listing_agent_commision_rate = 0.
                                method private selling_agent_commision_rate = 0.
                               
                                method get_asking_price = asking_price
                                method get_selling_price = selling_price
                               
                                method get_address = address
                               
                                method increase_asking_price_by amount =
                                        asking_price <- asking_price + amount
                                       
                                method decrease_asking_price_by amount =
                                        asking_price <- asking_price - amount
                                       
                                method set_selling_price amount =
                                        selling_price <- amount
                                       
                                method has_listing_agent = not !listing_agent#name_nil
                                method has_selling_agent = not !selling_agent#name_nil
                               
                                method get_listing_agent = !listing_agent
                                method get_selling_agent = !selling_agent
                               
                                method set_listing_agent new_agent =
                                        listing_agent <- ref new_agent
                               
                                method set_selling_agent new_agent =
                                        selling_agent <- ref new_agent
                                       
                                method sold = sold
                                method set_sold = sold <- true
                               
                                method as_string =
                                        if sold then
                                                Printf.sprintf "The property at %s sold for $%d" address selling_price
                                        else
                                                Printf.sprintf "The property at %s is for sal, asking $%d" address asking_price
                                       
                                method close =
                                        let listing_agent_commission =
                                                ((float_of_int selling_price) *. self#listing_agent_commision_rate) and
                                        selling_agent_commission =
                                                ((float_of_int selling_price) *. self#selling_agent_commision_rate) in
                                                if self#has_listing_agent && self#has_selling_agent then
                                                        begin
                                                                !listing_agent#add_commission listing_agent_commission;
                                                                !selling_agent#add_commission selling_agent_commission
                                                        end
                                                else if self#has_listing_agent then
                                                        let total_commission = listing_agent_commission +. selling_agent_commission in
                                                                !listing_agent#add_commission total_commission
                                                else
                                                        raise No_listing_agent;
                                                self#set_sold
                        end
                       
                class residential_property address init_asking_price =
                        object(self)
                                inherit basic_property address init_asking_price as super
                               
                                method private listing_agent_commision_rate = 0.02
                                method private selling_agent_commision_rate = 0.03
                        end
                       
                class rental_property address init_asking_price rental_income =
                        object(self)
                                inherit basic_property address init_asking_price as super
                               
                                method private listing_agent_commision_rate = 0.03
                                method private selling_agent_commision_rate = 0.03
                               
                                method rental_income = rental_income

                                method as_string =
                                        super#as_string ^ Printf.sprintf ", and offers annual rental income of $%d" rental_income
                        end
        end


A simple sample:

code:
open RealEstate
open Printf
include RealEstate

let prop = new residential_property "42 Oak St." 2_000
let lister = new agent "Bob Smith"
prop#set_listing_agent (ref lister)
prop#set_selling_price 3_000
prop#close

Printf.printf "Commission: %f\n" lister#total_commissions


O'Caml: Because static typing can be useful, but explicitly stating those types is lame.

Wink
Martin




PostPosted: Sat Aug 21, 2004 12:27 am   Post subject: (No subject)

How do I do java inheritance without protected variables?
wtd




PostPosted: Sat Aug 21, 2004 2:53 am   Post subject: (No subject)

Darkness wrote:
How do I do java inheritance without protected variables?


Properly.

For something this simple, the child class shouldn't need to directly access the parent class' instance variables. Rather you use the interface exposed by the parent class.

This is where accessors (get, set) come in handy. Smile
Martin




PostPosted: Sat Aug 21, 2004 9:44 am   Post subject: (No subject)

The inheritence that I was using was CRentalProperty extends CProperty.

Now, everything is the same as CProperty, except there is also an annual income.

How do I do this (efficiently) without using protected variables? And what's so bad about protected variables anyway?
rizzix




PostPosted: Sat Aug 21, 2004 11:49 am   Post subject: (No subject)

hmm nothing?!?
wtd




PostPosted: Sat Aug 21, 2004 8:49 pm   Post subject: (No subject)

Darkness wrote:
The inheritence that I was using was CRentalProperty extends CProperty.

Now, everything is the same as CProperty, except there is also an annual income.

How do I do this (efficiently) without using protected variables? And what's so bad about protected variables anyway?


I'm guessing they want to see if you can realize that you don't need protected variables in this case.

Why would CRentalProperty need to access the instance variables of CProperty?
wtd




PostPosted: Sat Aug 21, 2004 9:42 pm   Post subject: (No subject)

Feel free to peruse the attached file and comment freely.

Python version added.
Ruby version added.
Eiffel version added.

I love demonstrating the beauty of these languages. Smile



main.e.txt
 Description:

Download
 Filename:  main.e.txt
 Filesize:  4.58 KB
 Downloaded:  428 Time(s)


main.rb.txt
 Description:

Download
 Filename:  main.rb.txt
 Filesize:  2.51 KB
 Downloaded:  465 Time(s)


main.py.txt
 Description:

Download
 Filename:  main.py.txt
 Filesize:  2.45 KB
 Downloaded:  430 Time(s)


RealEstate.java
 Description:

Download
 Filename:  RealEstate.java
 Filesize:  4.64 KB
 Downloaded:  467 Time(s)

Display posts from previous:   
   Index -> Java
View previous topic Tell A FriendPrintable versionDownload TopicSubscribe to this topicPrivate MessagesRefresh page View next topic

Page 1 of 1  [ 13 Posts ]
Jump to:   


Style:  
Search: