help needed in organising a debugging contest

i m a part of a team which is resposible for oraganising a debugging contest in our college.this debugging conetst is solely based on C.

This contest will be held in two phases first phase will be consisting of a paper based test, which would have objective questions based on and some sample 'C' codes(of very few lines) having some errors,syntactical or logical and the task would be to identufy and write them on paper.

i m facing problem in deciding wat should be the format of the test in second phase.this phase would be held on computer systems.

the problems are basically-
-what kind of errors we can introduce in our test codes like only syntactical,logical,or both..also out of many other possible errors.

-how to make sure that after the code gets debugged it still is doing wat it was meant for.(i realise this cud b done using sample input cases..but hoe to decide the input cases)

-in case two ppl debug the code in same time how to decide which one has done it in a better way?

-can we introduce optimisation issues and if yes how in real scenario.

-how to frame questions.(taking an already existing codes and going in reverse way by introducing some errors or in some other better way..??)

-what sources can prove useful in deciding the frame design of the test...some books,links etc...if anyone can suggest.

thanks in advance for any help!

Quote:

---

-what kind of errors we can introduce in our test codes like only syntactical,logical,or both..also out of many other possible errors.

---

I'd go for some of each type, they each test a different skill.

Quote:

---

-How to make sure that after the code gets debugged it is still is doing what it was meant to do (I realise that this could be done using sample input cases. But how to decide the input cases).

---

Typos I can handle, but that looks like you're to lazy to even type out full words.

Well, if you want to give them what the out(?)put should look like, it's easy enough. Write a program, get your output, put in your errors.

Or else, just look at their final answer, see if it's a logical progression from the original. If you give them

Code:

---

cout < "test"

---

and they give you

Code:

---

cout << "test";

---

it looks pretty right to me. If instead they give you

Code:

---

printf("Hello World!");

---

that's wrong, and they get 0.

Quote:

---

-in case two ppl debug the code in same time how to decide which one has done it in a better way?

---

Which is shorter, which is faster, or just give them both the same mark.

Quote:

---

-can we introduce optimisation issues and if yes how in real scenario.

---

If you want to, it's your test. An example

Code:

---

if(x == 4 || x == 5)
{
    if(x == 4) //something
    if(x == 5) //something
    if(x == 6) //something
}
if(x == 4 || x == 5 || x == 6) //something else

---

It's a crappy example, but it should be easy enough to come up with something better.
Some ideas might be sorting algorithms, prime number generation, whatever, maybe some variations so they just don't copy down something they remembered from elsewhere.

Quote:

---

-how to frame questions.(taking an already existing codes and going in reverse way by introducing some errors or in some other better way..??)

---

That would probably be the easiest way, it gives you a definate end-point, what the code should look like and do. Remember to go through all the questions though, see if you can end up with something else.