1] If at all possible, don't. Let someone else do it.
2] Change majors.
3] Insert/remove blank lines at random spots, re-compile, and execute.
4] Throw holy water on the terminal.
5] Dial 911 and scream.
6] There is rumour that "printf" is useful, but this is probably unfounded.
7] Port everything to CP/M.
8] If it still doesn't work, re-write it in assembler. This won't fix the
bug, but it will make sure no one else finds it and makes you look bad.
-- How to debug a "C" program.