The Hardest 211 exam paper ever

I doubt that 80% of the students would fail. I think it will be more like 85%. They really tested time complexity in this exam. LESS time with INCREASED complexity.

*grin*

Yip, I agree the paper was hard(2005 mock exam was pissed compare to the 2006 exam) but not impossible (Maybe I should only speak after I received my marks ). Something that iratated me is that they asked us (Pretoria) in the middle of the exam to put away our pocket calculaters!

I’m actaully a bit pissed that they requested it in the middle of the exam. I even though of writing an official complaint to unisa because firstly they never said anywhere we may not use calculaters. They also broke my consetration without any reason and finally I like having a caclulater on my desk!

Can anybody maybe tell me why they requested that we should stop using calculaters? And did this happen anywhere else eg. Durban, Cape Town etc?

Has anybody received feedback from the lecturers???

Seemed liked a very poorly put together paper, either due to not enough time or poor quality control, Agree/disagree ???

Dam had nightmares about that paper last night.

I was also asked about half an hour into the exam to put away my calculator. How foolish was I for not completing question 1 before being asked that, thought I'd just come back

Does anybody know what the university's rules are for the use of calculators without any instructions regarding them being printed on the question paper? As far as I know, you can use them until it is explicitly stated that they may not be used. Thats my understanding. The problem with no explicit instruction is that the invigilators at some venues may not give a damn and allow students to use them while at other venues, students are told to put them away. This puts the latter group at a disadvantage. Lecturers setting the papers need to wake up to this and specify clearly what is and is not allowed, especially in tutorial letters to students before the exam and information sent to those invigilating.

the exam was hard,not impossible,with more time i think i wouldve done way better!i wanted to cry when the invigilator said time up,and i've only started the graph....with six nodes and then another two questions,i watched the 10marks evaporate.It was worse than breaking up with a boyfriend.God knows i don't want to do this again!!

Q4 c) had an error on the diagram instead of 83 they wrote 8,so it confused me for a bit coz i didn't know where the 8 came from,until i realized it must be a typo and time was already gone,my question is do i get the 7marks free coz their typo confused me and made my running time logarithmic?

& was in a rush,i saw quick sort and did pivot as middle..only realized this mistake later!

...true this was brutal in the sense that you can't expect people to rush on programming when they have to apply knowledge unlike biz management where its more like regurgitating stuff!

i guess unisa will be making double on COS211-X next year...maybe thats the plan!

..
NOW we deserve some feedback from the lecturers & the paper setters/correctors!!

don't hold your breath

Has anybody actually sent an email/phone/fax/sms/telegram to the lecturer(s) asking them what the story was? If not, would the person with the best diplomacy skills please volunteer?

Good point stevenv. Instead of ranting & raving in the forum did anyone contact someone official at UNISA?

I did email Lazarus Aron this morning.
Am waiting for a reply.

Reanie

Thanks Reanie,

If you would be so kind to let us know what u asked (So that if other students have other enquire) and what his reply was it would be greatly appreciated!

Mr Aron replied that he was not responsible for setting the exam paper. A senior lecturer did and he'll ask the person to comment on the forum.

Thanks alot Reanie.

I usually don't read post-exam comments till around January but I was told that there was a bit of animosity over the exam so I thought I'd take a look.

Wow. I didn't realise that there was such an outcry. I thought the exam was a bit long and a bit laborious.

I had a problem with the list swapping question and the graph question. Silly me didn't study graphs very well and I think I put the dotted arrows in wrongly.

If you had a problem with a particular question, you should have done what I did; for the node swap question, I stated where I found the question to be unclear, I told them my assumptions and told them my strategy for creating the solution and then I went for it. It was a bit long though. I'm sure the markers will take misunderstandings into account.

As far as the quicksort question was concerned, I don't understand how anybody could have a problem with it. If anything, having the pivot in the first slot saved some writing. If you think about it you'll see why. In the textbook example, the first step in partitioning the list is to move the pivot value to the first slot. This is not needed if the pivot is already in the first slot. The rest of the algorithm remains the same: create two sorted lists, one with values smaller than the pivot value, one with values greater than the pivot value. Once both lists are complete, put the pivot value between the two lists (swapping with the last value in the smaller-than list). Nothing really changes by having the pivot start in the first slot. In fact it doesn't really matter where the pivot starts from - it is always put in the first slot anyway.

Why would anybody need a calculator in this exam? And as far as I understand the rules, the default is to DISALLOW calculators in an exam unless the exam specifically says you can use one (anybody else done OPS or STA - it shows on the exam timetable that you're allowed a calculator)

blink wrote:
> I also felt a number of assumptions were made which shouldn't have
> been. Such as the mathematically what should happen if a negative
> number was passed into the recursive function. I'm fine with the
> coding but what is the "correct output?"
>
> I mean who knew that the correct mathematical answer would be
> something like return 1/functionName(a, -b);

hmmmm. If I remember the question correctly, the function went like:

int puzzle(int a, int b)
  {
  if (b == 0)
    return 1;
  else
    return a * puzzle(a, b - 1);
  }

Now. Try 3 examples:
puzzle(2, 3) = 8
puzzle(2, 0) = 2
puzzle(2, -3) = ???????????

No mathematics required, just an understanding of recursive functions. All recursive functions must have some way of terminating, otherwise they loop until you run out of stack memory. If b is zero, it returns 1 and stops the recursion. If b is posttive, it counts down till zero, which stops the recursion. If b is negative, it keeps getting more and more negative and recurs to infinity (theoretically).

Escay, where've you been this year, buddy? What happened?

Hi Rob,

I'm here, not too worry .... but hopefully I am not here next year again for COS211-X.

I must say, compared to the 2005 exam paper, this years paper was alot more difficult, and the time seemed much tighter. I woprked through the 2005 paper, and I completed that paper in 90 min ..... the 2006 one I didnt have enough time in 180 min ...

But I'll wait and see what the results look like before I start mouning anymore...

Cheers,
Esckay

Hi Rob,

About the recursive question that was working out a number to the power of another number.

They also asked you how you would fix it to work for negative numbers and the answer isn't that obvious (for me anyway).

if (b == 0) {
return 1;
} else if (b < 0) {
return puzzle(a,b+1) / a;
} else {
return a * puzzle(a, b - 1);
}

2^2 = 4
2^-2 = 0.25 (1/2/2)

So some calculations were required, although not that difficult.

To tell you the truth i think there has to be an explaination why the paper was set without taking time into account.I am doing COS211-X and INF320 this year.
Complexity-wise it was close to this year's sup paper...but it only went up to question 7 not 9!!
Personally i just needed more time,the material wasn't too complex for me but i wasn't given a chance to apply myself.
I'm not about to re-take this module- i have to graduate,i worked hard!!


take out '05 and '06 paper and lets compare.lets proof this was an unfair paper!

comparisons:

Q1-2005: you are dealing with hundreds you don't even need to work anything out on paper...2marks @
2006:you had to spend a couple of minutes multiplying to see
how the algorithms grow


Q2-2006:recursion similar to Q3-2005.difference.2005 free 10 marks but for 2006 you had to figure out a way to make the function's exponent positive and realize that 2^-2 is (1/2)^2.IF YOU DIDN'T REMEMBER THIS FROM HIGH SCHOOL,you had a bit of problem.I Had to force myself to remember!


Q3:2006 -fine!!


Q4(18 marks):MArk allocation here was bizzare,compare this with 2005-Q6(17marks) BUT IT DOESN'T MAKE SENSE TO COMPARE coz 2005-Q6 wasn't as severe or long.
Ok,make it long add 2005-Q6+Q4a(both linked list questions) and you get 30marks allocation.


Q5:2006-it was fine!
due to time constraints rushed thru it and by mistake took the middle element as pivot.


Q6:2006-The afrikaans made this question look like a novel took ages to figure out what is what.And i thought i would have time to come back to it -NAive ME!!


Q7:2006-it was fine.


Q8:2006-It was diffcult but it tokk long because unlike last year we had to draw and the marks didn't compensate for this??


Q9:2006-Who finished this question -seriously!!
for just 3additional marks as com,pared to last years we had to draw a graph and then traverse it!!i suppose it takes a micro-second to do that.
on top of that the shortest path graph was complex and took more time to duplicate.



Somebody needs to explain this deviation!!

Oh...i nearly forgot.i want to know for Q4c did anybody notice the error in the example diagram,instead of 83 the node was 8.
the diagram confused me and my invigilator wasn't sure its an error,wasted time asking,dunno why i bothered!

Didn't want to assume...should've!!

For that question i want my 7marks free...

Well at least I know I have the textbook and extra revision material for next year.
I learnt just a few days before the exam but that was my fault.
So those of you who really learnt well you deserve to pass
I still hope for the best but I know i'll probably fail. I tried my best in there

GOOD LUCK for the rest of the exams!

who set up the sup exam?
The same senior lecturer?