HL Computer Science Paper 1

[XeoKnight]

I have no idea how many of you do comp science, but how did it go? I found it ok., I guess. Section A could have been better, they asked the most obscure definitions imo (the syllabus mentions autonomous agents once, which I didn't pick up on) and was very, very different from the specimen. No dry run or truth tables either, both of which I was hoping to score easy marks on. I guess it went ok though, bsed a lot though so I'm not sure if I'll get full marks on the questions I answered

How did you guys feel about the queue question? I felt so lost, I had no idea what they wanted me to construct pseudocode of. I eventually figured I might as well make two methods (instead of one, like they said) as it didn't make sense to reload the queue each time he flicked the lever. But I guess it would change depending on the 48 hour rule thing, and that would involve checking whether the Stats[][] values are the same... ugh, I don't know. The 9 mark q on binary trees was nice though, even if I wasn't sure according to what they wanted me to sort the tree. I just went with alphabetical in the end.

[Sahil96]

How did you guys find paper 1. I thought it was difficult and included way more algorithms than usual. 5 (or 6 can't remember) instead of 2 or 3.

[David Kroell]

Well, I think that section A was okay, it was fair, except for that Autonomous agent stuff. No idea…

Algorithms I did my best on. Queues we had to know, and I memorized pseudo code for a queue that I just blotted down. A separate block of code for enqueuing and a separate one for dequeuing when the channel was flicked. although may have gotten my front and rear pointers mixed up. Which ever way, I thin that question was good. may have lost a few marks for the mix up of pointers.

Then we had that 'H' thing. What was that!!! I tried my best to follow it, it was so confusing. I put a loop counter while true to simulate the progression to the center of the screen and used a stack algorithm in pseudocode that again, I memorized from my notes. I had a real dedicated teacher.

I then drew an H with the side being 40 and bottom being 20, and I said that the permutation of H at 3 generations was 16 from 0 to 3 meant 4 endpoints squared. I got 16 for that one. I looped my original code for the drawing of H in the flow chart from 0 to 3 to represent H and 3 generations after that. Tried my best again on that one.

Then we had the nice questions with the binary trees and the sorting, I feel really bad though I didn't finish the 9 ark question completely. Really worried about that. Kind of freaking out… I got David fro the fifth stop said it was 5 euros. I sorted the binary tree alphabetically from Carlos Station.

What did you guys say for the linked list one. That was a great question but I only had two main sections of appending the table by adding the item to the bottom of the linked list and appending the ext node from the side as well.

SaaS - That question was nice… What was Extranet… I know VPN, but what's extranet??? All in all I'll be disappointed if I get below a 5 on this exam. Didn't really go the way I was expecting it to.

Please someone give me feedback, this is my major in University for crying out loud!!! I did the best I could.

[David Kroell]

I have no idea how many of you do comp science, but how did it go? I found it ok., I guess. Section A could have been better, they asked the most obscure definitions imo (the syllabus mentions autonomous agents once, which I didn't pick up on) and was very, very different from the specimen. No dry run or truth tables either, both of which I was hoping to score easy marks on. I guess it went ok though, bsed a lot though so I'm not sure if I'll get full marks on the questions I answered

How did you guys feel about the queue question? I felt so lost, I had no idea what they wanted me to construct pseudocode of. I eventually figured I might as well make two methods (instead of one, like they said) as it didn't make sense to reload the queue each time he flicked the lever. But I guess it would change depending on the 48 hour rule thing, and that would involve checking whether the Stats[][] values are the same... ugh, I don't know. The 9 mark q on binary trees was nice though, even if I wasn't sure according to what they wanted me to sort the tree. I just went with alphabetical in the end.

I put two methods as well for the queue. one for enqueuing and one for dequeueing. Stupid me though I think I go my front and rear pointers mixed up. … Binary tree said they wanted it in alphabetical order, so you're good. How did you do for the H one? did you use a while true loop like I did. I had a friend who used a boolean operator for the vehicles queue to simulate the flicking and such...

[XeoKnight]

Well, I think that section A was okay, it was fair, except for that Autonomous agent stuff. No idea…

Algorithms I did my best on. Queues we had to know, and I memorized pseudo code for a queue that I just blotted down. A separate block of code for enqueuing and a separate one for dequeuing when the channel was flicked. although may have gotten my front and rear pointers mixed up. Which ever way, I thin that question was good. may have lost a few marks for the mix up of pointers.

Then we had that 'H' thing. What was that!!! I tried my best to follow it, it was so confusing. I put a loop counter while true to simulate the progression to the center of the screen and used a stack algorithm in pseudocode that again, I memorized from my notes. I had a real dedicated teacher.

I then drew an H with the side being 40 and bottom being 20, and I said that the permutation of H at 3 generations was 16 from 0 to 3 meant 4 endpoints squared. I got 16 for that one. I looped my original code for the drawing of H in the flow chart from 0 to 3 to represent H and 3 generations after that. Tried my best again on that one.

Then we had the nice questions with the binary trees and the sorting, I feel really bad though I didn't finish the 9 ark question completely. Really worried about that. Kind of freaking out… I got David fro the fifth stop said it was 5 euros. I sorted the binary tree alphabetically from Carlos Station.

What did you guys say for the linked list one. That was a great question but I only had two main sections of appending the table by adding the item to the bottom of the linked list and appending the ext node from the side as well.

SaaS - That question was nice… What was Extranet… I know VPN, but what's extranet??? All in all I'll be disappointed if I get below a 5 on this exam. Didn't really go the way I was expecting it to.

Please someone give me feedback, this is my major in University for crying out loud!!! I did the best I could.

I found the Queue the hardest one not because the thing itself was hard, but because I couldn't wrap my head around what they wanted. They said they wanted code to do that stuff, but I was thinking that the whole code is run when he flicks the lever, but that makes no sense since that would reload everything in the queue again instead. I did decide to do two methods later on but I didn't finish that as I went back to it in the end

The H thing was really weird, but in the end I did a recursive sequence with the base case being size = 5, which would have been when the size was divided by 2 twice, so three generations or something like that. They then asked how you would do it recursively... so idk if I did it weirdly

Linked List I used a simple diagram with the boxes, pointers and nodes, showing stuff with temporary pointers and all. An extranet was sort of like a part of a company's intranet made available to its customers/public or something. It gives partial or limited access to it. I think the grade boundaries will be <75 anyway for a 7, so it shouldn't go too bad. It was 69% last year, and considering we have a new syllabus it may even go lower.

Edited May 17, 2014 by XeoKnight

[David Kroell]

Well, I think that section A was okay, it was fair, except for that Autonomous agent stuff. No idea…

Algorithms I did my best on. Queues we had to know, and I memorized pseudo code for a queue that I just blotted down. A separate block of code for enqueuing and a separate one for dequeuing when the channel was flicked. although may have gotten my front and rear pointers mixed up. Which ever way, I thin that question was good. may have lost a few marks for the mix up of pointers.

Then we had that 'H' thing. What was that!!! I tried my best to follow it, it was so confusing. I put a loop counter while true to simulate the progression to the center of the screen and used a stack algorithm in pseudocode that again, I memorized from my notes. I had a real dedicated teacher.

I then drew an H with the side being 40 and bottom being 20, and I said that the permutation of H at 3 generations was 16 from 0 to 3 meant 4 endpoints squared. I got 16 for that one. I looped my original code for the drawing of H in the flow chart from 0 to 3 to represent H and 3 generations after that. Tried my best again on that one.

Then we had the nice questions with the binary trees and the sorting, I feel really bad though I didn't finish the 9 ark question completely. Really worried about that. Kind of freaking out… I got David fro the fifth stop said it was 5 euros. I sorted the binary tree alphabetically from Carlos Station.

What did you guys say for the linked list one. That was a great question but I only had two main sections of appending the table by adding the item to the bottom of the linked list and appending the ext node from the side as well.

SaaS - That question was nice… What was Extranet… I know VPN, but what's extranet??? All in all I'll be disappointed if I get below a 5 on this exam. Didn't really go the way I was expecting it to.

Please someone give me feedback, this is my major in University for crying out loud!!! I did the best I could.

I found the Queue the hardest one not because the thing itself was hard, but because I couldn't wrap my head around what they wanted. They said they wanted code to do that stuff, but I was thinking that the whole code is run when he flicks the lever, but that makes no sense since that would reload everything in the queue again instead. I did decide to do two methods later on but I didn't finish that as I went back to it in the end

The H thing was really weird, but in the end I did a recursive sequence with the base case being size = 5, which would have been when the size was divided by 2 twice, so three generations or something like that. They then asked how you would do it recursively... so idk if I did it weirdly

Linked List I used a simple diagram with the boxes, pointers and nodes, showing stuff with temporary pointers and all. An extranet was sort of like a part of a company's intranet made available to its customers/public or something. It gives partial or limited access to it. I think the grade boundaries will be <75 anyway for a 7, so it shouldn't go too bad. It was 69% last year, and considering we have a new syllabus it may even go lower.

I used a while true loop for the H. When I had to do it two three generations after I just looped the entire thing 3 times over the other loop. Thus like you said, a nested loop.

loop from 0 to 3

loop while true

if Stack is not empty

H.pop(Stack)

else

break;

end if

end loop

end loop

I did something like that for the 3 generations. According to what Ive said, do you think I did well, the great thing about this exam is that the grade boundaries shouldn't change much.

[PhilB]

I'm glad other people had similar problems as me in regards to Section B. My teacher had luckily given me readings on autonomous agents about 2 weeks ago so I was able to complete that question without too much issue.

I also had issues with the extranet question and the Queue section of the radio question but I'm hoping my partially correct solutions are good for a couple of marks.

On the linked list question I had a diagram explaining something like i.next = p.next and i.next = p where i was the element directly to the left of the location where p was being inserted.

I think I had the algorithm down for the H question by using a combination of nested loops and the code directly above the question. I had 4^4 or 256 endpoints but that was more of a guess than anything.

On the final question I had an algorithm that was something like this simplified version,

if (LocationA.Line == LocationB.Line){     fare = abs(LocationA.zone-LocatonB.zone)}else{     fare = LocationA.Zone + LocationB.Zone + 1}

[XeoKnight]

I used a while true loop for the H. When I had to do it two three generations after I just looped the entire thing 3 times over the other loop. Thus like you said, a nested loop.

loop from 0 to 3

loop while true

if Stack is not empty

H.pop(Stack)

else

break;

end if

end loop

end loop

I did something like that for the 3 generations. According to what Ive said, do you think I did well, the great thing about this exam is that the grade boundaries shouldn't change much.

So you coded a stack just for this? Pretty impressive, under that time limit. I think the examiners should take it, as long as it does it there is no reason for them not to, and tbh even if you missed 40 marks you'd get 60%, so there is no way you got lower than a 6 I think (if a 6 is not >60%, not sure about that).

[David Kroell]

Well, I think that section A was okay, it was fair, except for that Autonomous agent stuff. No idea…

Algorithms I did my best on. Queues we had to know, and I memorized pseudo code for a queue that I just blotted down. A separate block of code for enqueuing and a separate one for dequeuing when the channel was flicked. although may have gotten my front and rear pointers mixed up. Which ever way, I thin that question was good. may have lost a few marks for the mix up of pointers.

Then we had that 'H' thing. What was that!!! I tried my best to follow it, it was so confusing. I put a loop counter while true to simulate the progression to the center of the screen and used a stack algorithm in pseudocode that again, I memorized from my notes. I had a real dedicated teacher.

I then drew an H with the side being 40 and bottom being 20, and I said that the permutation of H at 3 generations was 16 from 0 to 3 meant 4 endpoints squared. I got 16 for that one. I looped my original code for the drawing of H in the flow chart from 0 to 3 to represent H and 3 generations after that. Tried my best again on that one.

Then we had the nice questions with the binary trees and the sorting, I feel really bad though I didn't finish the 9 ark question completely. Really worried about that. Kind of freaking out… I got David fro the fifth stop said it was 5 euros. I sorted the binary tree alphabetically from Carlos Station.

What did you guys say for the linked list one. That was a great question but I only had two main sections of appending the table by adding the item to the bottom of the linked list and appending the ext node from the side as well.

SaaS - That question was nice… What was Extranet… I know VPN, but what's extranet??? All in all I'll be disappointed if I get below a 5 on this exam. Didn't really go the way I was expecting it to.

Please someone give me feedback, this is my major in University for crying out loud!!! I did the best I could.

I found the Queue the hardest one not because the thing itself was hard, but because I couldn't wrap my head around what they wanted. They said they wanted code to do that stuff, but I was thinking that the whole code is run when he flicks the lever, but that makes no sense since that would reload everything in the queue again instead. I did decide to do two methods later on but I didn't finish that as I went back to it in the end

The H thing was really weird, but in the end I did a recursive sequence with the base case being size = 5, which would have been when the size was divided by 2 twice, so three generations or something like that. They then asked how you would do it recursively... so idk if I did it weirdly

Linked List I used a simple diagram with the boxes, pointers and nodes, showing stuff with temporary pointers and all. An extranet was sort of like a part of a company's intranet made available to its customers/public or something. It gives partial or limited access to it. I think the grade boundaries will be <75 anyway for a 7, so it shouldn't go too bad. It was 69% last year, and considering we have a new syllabus it may even go lower.

I used a while true loop for the H. When I had to do it two three generations after I just looped the entire thing 3 times over the other loop. Thus like you said, a nested loop.

loop from 0 to 3

loop while true

if Stack is not empty

H.pop(Stack)

else

break;

end if

end loop

end loop

I did something like that for the 3 generations. According to what Ive said, do you think I did well, the great thing about this exam is that the grade boundaries shouldn't change much.

I don't know if we should have done a recursive method for it. Because, they specified a single thread of code would be necessary. They then later on asked us how we would implement it as a recursive method. I said because every generation is the same size as the H before it , it mimics the code. They pointed that out clearly in the instructions when presenting the other code. I couldn't really understand what all that code was there for. Oh well, this was a blow out. Been feeling really depressed the last couple of days. Computer Sceince was something I was good at…

[David Kroell]

You guys seem to know you're stuff. It's been a privilege to be one of the first computer Sceince Student along with you. Good luck!

Paper 2 tomorrow. Databases! Yay! NOT!!!

[Guest]

tbh I don't know what to think anymore... I feel the same way you do, David - I thought I was pretty good at this stuff haha. Unfortunately... I didn't have as dedicated a teacher so I felt very underprepared for section B, though I think I managed to hit most points for the last question, versus the H question. I feel like the section B questions weren't worded very well; I spent more time trying to understand what they wanted from me than trying to figure out the pseudocode.

You guys seem to have had a better handle on section B than I did - gg there

Good luck for paper 2 and 3 tomorrow everyone!

[Guest joh1224]

OMG reading all your stuff makes me feel so stupid. Throughout the whole exam i was like WTF IS THIS??? But that was probably because I was so braindead after Geography. I especially messed up the last algorithm about calculating fares between stations.

Grade-Boundaries are gonna be really low this year, or at least i hope so. Also hope for partial-marks...

Good luck on Paper 2!

[dsmurphy]

I felt like my teacher didn't prepare me well for the pseudo code at all, but then we thought there would be a lot less based on the Spec paper. I feel like if you did OOP for options you were a bit better prepared for this test, but we did Web Science :/

I'm just hoping to do well on the case study and option paper tomorrow

[XeoKnight]

OMG reading all your stuff makes me feel so stupid. Throughout the whole exam i was like WTF IS THIS??? But that was probably because I was so braindead after Geography. I especially messed up the last algorithm about calculating fares between stations.

Grade-Boundaries are gonna be really low this year, or at least i hope so. Also hope for partial-marks...

Good luck on Paper 2!

FINALLY ONE OTHER PERSON! I did geo as well although my geography was after comp science, not before. Led to me being brain-dead for geo instead

[Ho Lee]

What are the penalties for writing the code NOT in pseudocode??

For example, for a 9pts question, your algorithm is correct but is written in a non-pseudocode format....?

[Ho Lee]

GOOD LUCK IN PAPER 2 AND 3 TOMORROW EVERYONE!!!!!!!!!!!!!! 14 MORE HOURS TO GO!!!

[David Kroell]

What are the penalties for writing the code NOT in pseudocode??

For example, for a 9pts question, your algorithm is correct but is written in a non-pseudocode format....?

Don't worry, there is no penalty for writing in java or anything. you need to write it in a higher level language, that's all. Syntax has no bearing on the marks you get. It's all Computational thinking and logic.

[David Kroell]

I used a while true loop for the H. When I had to do it two three generations after I just looped the entire thing 3 times over the other loop. Thus like you said, a nested loop.

loop from 0 to 3

loop while true

if Stack is not empty

H.pop(Stack)

else

break;

end if

end loop

end loop

I did something like that for the 3 generations. According to what Ive said, do you think I did well, the great thing about this exam is that the grade boundaries shouldn't change much.

So you coded a stack just for this? Pretty impressive, under that time limit. I think the examiners should take it, as long as it does it there is no reason for them not to, and tbh even if you missed 40 marks you'd get 60%, so there is no way you got lower than a 6 I think (if a 6 is not >60%, not sure about that).

Well I didn't really code the entire stack.

I followed what the flow chart stated, that it would draw H in the center and if H was in the center and the stack was empty, it would break the loop and output yes or something like that. I used the syntax pop, from the data booklet. They should really let us have a pseudocode data bookelt in the exam.

[Guest joh1224]

I am doing OOP tomorrow,... but after Geo again

I am literally eating all the algorithms of the past years for breakfast, lunch and dinner.

U know the IB fired the people who wrote the Spec-papers?? Crazy!

[David Kroell]

I am doing OOP tomorrow,... but after Geo again

I am literally eating all the algorithms of the past years for breakfast, lunch and dinner.

U know the IB fired the people who wrote the Spec-papers?? Crazy!

No way! They couldn't give us a spec paper that was more like this exam then?