COMP5212 Resources

Bonus questions, templates, example solutions

This page provides some stuff about programming in Python and C for the COMP5212 course.

You may view your marks here (updated 30 May 2009).

In week 13 lab (4 June), I will give some bonus questions in lab, for people who are interested to get some bonus marks. If you're interested in attempting those questions, I strongly recommend you to (nearly) complete your lab work from home. You may want to learn about bitwise operators to have a better chance solving some of the questions; here is a tutorial by Dave Marshall.

Example code for labs and homework

• week 3: lab homework
• week 4: lab homework
• week 5: lab homework
• week 6: lab homework homework-2
• week 7: lab lab-2 lab-3 homework homework-2
• week 8: lab homework
• week 9: lab
• week 10: lab
• week 11: lab homework
• week 12: lab homework

FAQ

• Q: What are the recommended gcc flags to compile my C program?
  A: gcc -Wall -W -ansi -pedantic -g myProgram.c -o myProgram
• Q: What does week 7 homework really want us to do?
  A: In short, it wants a program that prints every other line of the input until a line starting with 'Q'. It is probably easier to illustrate this by sample input/output:

  1
  1
  a
  123ab
  123ab
  abcd
  Q456

  Lines 2 and 5 are output. The last line starts with 'Q', so the rest of it was not read in.
• Q: How do I develop C programs under Windows?
  A: There are a number of C compilers you can obtain free of charge. If you would like to use GCC (and I do recommend this compiler), you will need either MinGW or Cygwin (refer to GCC's download page).
• Q: What is sample input/output for Week 8 homework?
  A:

  ~$ ./homework8
  1 2 3 4
  a b c
  <EOF>
  Number of spaces: 5

  Where an EOF character is Ctrl-D (on *nix systems) or Ctrl-Z (on Windows). You might need to hit Enter after Ctrl-Z on Windows.
• Q: Can I connect to SIT's machines?
  A: You may use an ssh client, such as putty, to connect to a number of SIT's machines, including congo[1-4].ug, userf[1-5].ug, ufiler[0-4].ug. So, for example, congo1.ug.it.usyd.edu.au is a machine you can access, and ufiler2.ug.it.usyd.edu.au is another one. The login is the same as the one you use in the regular lab.
• Q: My C program compiles in [blah] (substitute this with any C compiler other than GCC, such as Visual C++), but not GCC!
  A: Each compiler differs slightly and may provide some non-standard libraries and/or functions. So, the best thing is to compile your C programs with GCC (refer to an FAQ about installing GCC on Windows). Alternatively, you could remotely access an SIT's machine (again, refer to an FAQ above) and write your C programs with a command-line editor, such as nano, emacs or vim.
• Q: Can I have text highlighting in nano?
  A: Yes, by the use of a configuration file. Here is an example of the file: dot_nanorc. Copy that file and save it under your home directory (i.e. "~/") as ".nanorc".

Other lab-related sources

• Australian postcode database: Auspost postcode
  Here is a hack to convert the file into the desirable format for week 5 and 6 lab/homework: postcode_hack.py. Just run the file with the unzipped postcode database (i.e. pc-full_200900331.csv) in the same directory. The file "postcodes" would be generated.

Python and C documentations and references:

• Python Quick Reference 2.4, 2.5, 2.6
• Official Python Docs, particularly useful are: Language reference and Library reference
• C/C++ library reference
• and you can always check out the resources section of the course's official page.

Programming and debugging tips

• Comment your code consistently and succinctly. This also helps youself understand what you try to do.
• Pseudo-code before actually coding. This helps make sure the logic is correct.
• Insert some sort of debug prints regularly. It helps debug.
• Paper debug: step through your program with a pen and paper.

Practice programming questions

Here are some sites that contains some programming questions to practice.

• A few questions from Westminister School of IT website: here
• Some questions of simple computer AI, although many of them do not have sample input/output, which makes them confusing. problems
• UVa Online Judge: lots of questions, ranging from challenging to very challenging! You could also submit your answers to the automatic judging system, with a free login.