Software Design & Development Marathon [2012] (2 Viewers)

[SpiralFlex]

Due to the lack of reception with my previous thread, hopefully more people will contribute as more SDD students join the forum. Year 12s and Year 11s and anything below and beyond feel free to participate.

I shall start,

An algorithm is required to fill an n by n two-dimensional array of Boolean values so that the diagonals each contain True and all other array elements remain False. It is known that all elements are initially false. The required result when n=6 (ie. a 6 by 6 array) is reproduced below.

n=6	0	1	2	3	4	5
0	True	False	False	False	False	True
1	False	True	False	False	True	False
2	False	False	True	True	False	False
3	False	False	True	True	False	False
4	False	True	False	False	True	False
5	True	False	False	False	False	True

Write an algorithm that will efficiently achieve this requirement.

Note: To type code in psuedo, the preferred method when using a forum is to use [code.] at the beginning of your code and [/code.] at the end of your code. No full stops.

BEGIN Spiralsays

   PRINT Like this kekeke

END Spiralsays

 

[ahdil33]

So being active on this thread. After I finish 3u.

 

[MrBrightside]

Good luck guys, and don't stress too much. Know your algorithms for the searches and sorts.

 

[Cyberbully]

A plane P is flying at a constant speed of 8gh m/s upwards at an angle of elevation of 30 degrees.

At the instant when the plane is at a height h metres vertically above a missile silo located at a point O on the ground, a missile from the silo is launched at an angle of elevation E to hit the plane where 0 < x < 90 .

Describe the function of a flip flop.

 

[GoldyOrNugget]

*Flexes his algorithm muscles, cracks neck. mmmmmm*

Excuse my dodgy pseudocode.

BEGIN Fill(Table, n)
  FOR r=0 TO n-1
    Table[r][r] = TRUE
    Table[r][n-r-1] = TRUE
  NEXT r
END Fill

 

[sddmoustache]

Discuss the impact of reverse engineering on software developers. (2 marks?)

 

[sddmoustache]

hCab is an online taxi service website that offers cheaper taxi fares if customers order online. hCab classifies its members as either normal or GOLD. A member is normal by default. A member becomes a GOLD hCab member if that user has been a member for more than 5 weeks and he/she has ordered 10 or more taxis from hCab. It is known that there are 100 hCab members. hCab stores its members in an array of records called Members, with the following fields:

Name: the name of the member
MemberFor: the number of days that the user has been a member at hCab for
Transactions: the number of times the user has ordered a taxi from hCab

Write a subroutine CountGoldMembers(Members, NumberOfGold) that counts the number of Gold hCab members in the Members array.

 

[GoldyOrNugget]

Are we meant to be answering questions in this thread? Or just posting questions?

 

[ahdil33]

This is my solution for the first question.

BEGIN code (array, n)
    For i = n to n-1
       arr(i,i) = true
       arr(i, n-1-i) = true
    Next i
END

 

[SpiralFlex]

Are we meant to be answering questions in this thread? Or just posting questions?

The tradition is to post questions then a person answers and another person can post a good question and then someone else answers and repeat. This gives people practice.

 

[ahdil33]

Discuss the impact of reverse engineering on software developers. (2 marks?)

Reverse engineering involves the breaking down of a software solution in order to understand how it works, and as such often breaches the intellectual property rights of the original software developers as others may develop similar products. This may lead to a lack of profits for the software developers, and may also lead to software developers being discouraged to further create software solutions.

 

[ahdil33]

hCab is an online taxi service website that offers cheaper taxi fares if customers order online. hCab classifies its members as either normal or GOLD. A member is normal by default. A member becomes a GOLD hCab member if that user has been a member for more than 5 weeks and he/she has ordered 10 or more taxis from hCab. It is known that there are 100 hCab members. hCab stores its members in an array of records called Members, with the following fields:

Name: the name of the member
MemberFor: the number of days that the user has been a member at hCab for
Transactions: the number of times the user has ordered a taxi from hCab

Write a subroutine CountGoldMembers(Members, NumberOfGold) that counts the number of Gold hCab members in the Members array.

BEGIN CountGoldMembers(Members, NumberofGold)
    NumberOfGold = 0
    FOR i = 0 to 99
        IF Members(i).MemberFor => 35 THEN
              IF Members(i).Transactions => 10 THEN
                   NumberOfGold = NumberOfGold + 1
              ENDIF
        ENDIF
    NEXT i
    RETURN NumberOfGold
END CountGoldMembers

Did I miss anything? I assumed the database started from index 0.

 

[ahdil33]

A plane P is flying at a constant speed of 8gh m/s upwards at an angle of elevation of 30 degrees.

At the instant when the plane is at a height h metres vertically above a missile silo located at a point O on the ground, a missile from the silo is launched at an angle of elevation E to hit the plane where 0 < x < 90 .

Describe the function of a flip flop.

Notsurewhatsubject.

 

[SpiralFlex]

Notsurewhatsubject.

Combination of half a projectile motion question and the 2nd option topic which does not relate in any way.

 

[ahdil33]

Combination of half a projectile motion question and the 2nd option topic which does not relate in any way.

And the function of a flip flop, lol haha

Anyone got any algorithm questions which aren't from the HSC? Other than the screweed up Indepedent ones haha. Not really comfortable with algorithms combined with opening/appending/closing files :s

 

[SpiralFlex]

And the function of a flip flop, lol haha

Anyone got any algorithm questions which aren't from the HSC? Other than the screweed up Indepedent ones haha. Not really comfortable with algorithms combined with opening/appending/closing files :s

I think there should be some good problems in the Informatics Olympiad. (Ask Goldy) I'll post some questions (interesting ones) after I watch some good anime movies.

Also just wanted to say thanks for participating guys - keep the questions and answers flowing. This subject is quite cool! Don't know why it cops a lot...

 

[ahdil33]

I think there should be some good problems in the Informatics Olympiad. (Ask Goldy) I'll post some questions (interesting ones) after I watch some good anime movies.

Also just wanted to say thanks for participating guys - keep the questions and answers flowing. This subject is quite cool! Don't know why it cops a lot...

I guess it's mainly because people figure it should have more on the 'design' side, with actual programming, which is what they came for, as opposed to the focus on the whole development cycle. Not necessarily a bad thing though. This is just what people in my class complain about.

 

[SpiralFlex]

I guess it's mainly because people figure it should have more on the 'design' side, with actual programming, which is what they came for, as opposed to the focus on the whole development cycle. Not necessarily a bad thing though. This is just what people in my class complain about.

Yup - I would love to see the course have a Sect I on Multiple choice to cover a bit of social and ethical stuff and coding. Section II could be some coding problems in pseudocode and a small mixture of computer science and the last section sort of like an elective where they ask you questions on a prescribed language - analogous to your prescribed texts in English.

 

[ahdil33]

Yup - I would love to see the course have a Sect I on Multiple choice to cover a bit of social and ethical stuff and coding. Section II could be some coding problems in pseudocode and a small mixture of computer science and the last section sort of like an elective where they ask you questions on a prescribed language - analogous to your prescribed texts in English.

The option topic being a language you choose, I like that.

The MC thing wouldn't work as well though, because people would just not study for it and just instead study for the SDD thing. I'd say as it is it's alright, just get more programming into it, from like the 15% it is more to 40%+

 

[GoldyOrNugget]

Do people want real (as in, not HSC-level) algorithms questions? They probably won't be much help for SDD specifically -- they test high-level mathematical reasoning more than anything else.

Here are three nice ones off the top of my head. The first 2 could in theory come up in an SDD exam, I guess. There are lots of approaches for the third one, some easier than others.

EASY: Write a function that finds the sum of all multiples of 3 or 5 below a given n. (source: adapted from Project Euler question 1)

EASY-MODERATE: Write a function that, given n, finds the nth fibonacci number. Start at 1,1,2,3.... (source: classic)

HARD: You are given an n*n grid G of integers, where in any row r, and in any column c, . Efficiently determine whether a given integer k is in the grid. (Source: one of the UNSW third-year algorithms course practice papers)

EDIT: ahdil if you're interested in computing at UNSW you should give these a go. I'll see you next year