D1 (Decision 1) 17 May 2013 Official Thread

No you sometimes they want you to find the number of minimum workers needed , sometime they say use your gantt chart to do that but sometimes even if u want to use the lower bound it does not give u the same number of workers sometimes when u use the gantt you need 4 workers and in lower bound you get 3 why the difference

No you sometimes they want you to find the number of minimum workers needed , sometime they say use your gantt chart to do that but sometimes even if u want to use the lower bound it does not give u the same number of workers sometimes when u use the gantt you need 4 workers and in lower bound you get 3 why the difference

What is coming up for sure? IMO bubble sort must come up and drawing the CPA

Okay guessing time. Here is what I expect to come up in the exam tomorrow.

Definitions - they love the reason for a dummy definition but I would expect definition on algorithms on networks or matchings.

Kruskal's, that is pretty certain to come up. Make sure you know the differences between Prim's and Kruskal's.

Sorting algorithm, you will either get Bubble or Quick, probably numerical descending order, which is likely to lead into...

Bin Packing - Make sure you know how to find the lower bound / proving a solution is maximal.

CPA - Maybe drawing an activity network and my money would be on a Gantt. Make sure you know how to find a lower bound from the activity network AND from a Gantt.

Linear Programming - Hammer linear programming, it is on every paper and is often the poorest answered. Unless you know how to go from context to a restriction you could be absolutely stuffed. Also make sure you know the basics, y = mx + c, if you don't know how to draw a line, do a table of values! you only need 3 points. I wouldn't be surprised if you get a decimal point but require an integer solution, so practise these.

I'm going to lose so many marks if I don't sort out my notation.

Can someone PLEASE answer this question:

When you're doing Dijkstra's algorithm and you have, let's say, point G with a working value of 15. Then the second working value you do is bigger than 15, do you still write it in and cross it out? Or do you just leave it out completely?!

Thank you! x

Since IWantSomeMushu has brought it up, does anyone know what on earth is going on with the numbering of nodes in activity networks? Are we marked on how we have numbered our nodes, or is that just for personal reference.

Also what is the procedure, do I label them in ascending order as I plot the network I hope it's not compulsory

Can someone PLEASE answer this question:

When you're doing Dijkstra's algorithm and you have, let's say, point G with a working value of 15. Then the second working value you do is bigger than 15, do you still write it in and cross it out? Or do you just leave it out completely?!

Thank you! x

If it is bigger then don't write it in at all.

My teacher tells me that you should always write every working value you obtain - even if it is bigger than your lowest working value, just put it in brackets... .

Imagine you get 26 then 23 then 24, you would write 26 [space] 23 [space] then (24) - note the brackets... .

Don't give them an excuse to take a mark off you!!

Out of curiosity, I hope it doesn't come up bearing in mind, what do you do if you get two critical activities occurring at the same time? For a Gantt chart do you just draw them on different lines?

Thanks!

Toby

Yes you draw it underneath the critical activities

Thank you! And also, you're right about the cross for the larger working values, I have done that before in a mock and it worked out! As long as you make it stand out I doubt it'll be a problem including it... .

Toby

My teacher tells me that you should always write every working value you obtain - even if it is bigger than your lowest working value, just put it in brackets... .

Imagine you get 26 then 23 then 24, you would write 26 [space] 23 [space] then (24) - note the brackets... .

Don't give them an excuse to take a mark off you!!