[ms607]

(Original post by SecondHand)
How do you guys know your UMS for your coursework? Did you submit it in January?

Do you have one of them crazy offers from Imperial?

they only know the mark the teacher gave them, it might be scaled up or down

my teacher never told me my provisional mark

[henrylee]

When is hashing mentioned in the book other than the bit to do with digital certificate? anyone got a method for infix to postfix and vice versa?

[FredrickTrott]

(Original post by SecondHand)
How do you guys know your UMS for your coursework? Did you submit it in January?

Do you have one of them crazy offers from Imperial?

Like it was mentioned in one of the earlier posts, it is a provisional mark given by the teacher, however my teacher is quite good as estimating what we get, last years class got exactly what he worked out for them, no one was marked up or down, which is a shame, as i would like to be marked up .

Yeah my offer isn't as terrible as some i have heard on tsr, i need an A* in F.Maths, A in Physics, and an A from Comp or Chemistry. So Manageable, but it also means i have to work hard for the Further Maths A* .

What Uni's have you firmed and insured?

[FredrickTrott]

(Original post by henrylee)
When is hashing mentioned in the book other than the bit to do with digital certificate? anyone got a method for infix to postfix and vice versa?

It isn't mentioned in the book, as according to our ex-head of Computing (He wrote the book) It was too large a chapter to fit in the book.

All the necessary material you need can be found here :

http://store.aqa.org.uk/qual/gce/pdf...-COMP3HASH.PDF

[SecondHand]

(Original post by FredrickTrott)
Like it was mentioned in one of the earlier posts, it is a provisional mark given by the teacher, however my teacher is quite good as estimating what we get, last years class got exactly what he worked out for them, no one was marked up or down, which is a shame, as i would like to be marked up .

Yeah my offer isn't as terrible as some i have heard on tsr, i need an A* in F.Maths, A in Physics, and an A from Comp or Chemistry. So Manageable, but it also means i have to work hard for the Further Maths A* .

What Uni's have you firmed and insured?

I firmed Oxford.

When is hashing mentioned in the book other than the bit to do with digital certificate? anyone got a method for infix to postfix and vice versa?

Infix to postfix is nasty, uses an algorithm devised by dijkstra called the Shunting-yard algorithm. On the other hand, postfix(RPN) is dead easy, which is why it's used. Construct a parse tree and then perform an inorder traversal, this doesn't solve the ambiguity of infix.

[SecondHand]

Here's a revision notes framework my teacher made. They go with the official textbook.
https://dl.dropbox.com/u/6280195/Learning%20Grids.doc
https://dl.dropbox.com/u/6280195/Lea...%20Answers.doc

[Edwin Okli]

(Original post by FredrickTrott)
It isn't mentioned in the book, as according to our ex-head of Computing (He wrote the book) It was too large a chapter to fit in the book.

All the necessary material you need can be found here :

http://store.aqa.org.uk/qual/gce/pdf...-COMP3HASH.PDF

Surely that's the worst reason to not include a topic. I mean, if hashing does come up next week (which it will if they are ever going to test on it), then you can expect to see the raw to UMS scale shift so that 100% is even less than it is at the moment.

I'll join in on this anxiety trend we've got going. I got an A* in my mock (actually full UMS) but I'm still stupidly nervous.

[ms607]

(Original post by SecondHand)
Here's a revision notes framework my teacher made. They go with the official textbook.
https://dl.dropbox.com/u/6280195/Learning%20Grids.doc
https://dl.dropbox.com/u/6280195/Lea...%20Answers.doc

Finally!!! I've been looking for answers to the learning grids for ages, thanks

[exam2k10]

Am I the only one who is nervous for this exam?

Thing with me is that Im nervous for every exam, walk in the exam hall and then come results day I do a lot better than expected.

ATM, Im just recapping the network chapter. Is interesting as I have some practical knowledge and also used to set up routers for family friends, of course free of charge since I am a complete network noob .

This is what I think will come up next week...

• Abstraction + Info Hiding
• Algorithms
• BNF, RPN
• FSM, Turing Machine
• OOP (They havent asked much. I say they will make us draw class and inheritance diagrams)
• Recursion (Definently this. If not a simple trace table. Make sure u practice on this though)
• Binary Tree (They havent asked this)
• Hashing
• Real Numbers (Involving negative numbers. Will be very straight forward)
• OS (Will be straight forward, but they may ask us to write an essay )
• Database (SQL, maybe some normalising)
• Networks

[agent87]

Anyone doing WJEC computing. Pretty much same stuff.

[exe]

(Original post by FredrickTrott)
It isn't mentioned in the book, as according to our ex-head of Computing (He wrote the book) It was too large a chapter to fit in the book.

All the necessary material you need can be found here :

http://store.aqa.org.uk/qual/gce/pdf...-COMP3HASH.PDF

I want to slap your ex head of computing so hard. He's so, so, so bad at writing.

[ngnav]

(Original post by FredrickTrott)
It isn't mentioned in the book, as according to our ex-head of Computing (He wrote the book) It was too large a chapter to fit in the book.

All the necessary material you need can be found here :

http://store.aqa.org.uk/qual/gce/pdf...-COMP3HASH.PDF

Do we need to know the full theory behind hashing, or just know how to use the hash tables?

[Yash13]

(Original post by ngnav)
Do we need to know the full theory behind hashing, or just know how to use the hash tables?

I thought we just had to learn what the hash function, hash tables are and what a collision is. What sort of questions have come up about hashing in the past?

[exe]

(Original post by Yash13)
I thought we just had to learn what the hash function, hash tables are and what a collision is. What sort of questions have come up about hashing in the past?

Basically nothing

Wish the spec was more specific - hope they get a new chief examiner

[ngnav]

In hashing, is the data stored in memory locations, or a hash table?

[compy]

For what it's worth, wikibooks has an incomplete hashing section with some simple questions and some diagrams:

http://en.wikibooks.org/wiki/A-level...ncepts/Hashing

[exe]

(Original post by ngnav)
In hashing, is the data stored in memory locations, or a hash table?

your question is kinda vague. data is always stored in "memory locations"
a hash table is just a table in which the unique identifier is the hash value of the key

[SecondHand]

This would be the first year they ask about hashing so they woudn't go in too hard.. I expect questions like, here is a hash function.. add these 5 items to the hash table.. snap there is a collision what do you do.. oh crap I need to delete an item what do I do.. I can't see them getting much deeper than that. I suppose the more advanced questions would be to do with the size of the hash table you need, maybe the order of accessing items from a hash table.

[exam2k10]

For hashing, for a open collision do you do a linked list and for a closed collision do you find the next available memory location?

BTW, even though I don't bet with people , I have a very strong feeling that hashing and also binary trees will come up. Will actually laugh hard if it comes in our exam.

[exe]

(Original post by exam2k10)
For hashing, for a open collision do you do a linked list and for a closed collision do you find the next available memory location?
.

yes