I was interviewed by a big internet company. After describing the problem to solve, the interviewer requested that I also submit test cases with the code via email.
I'm not sure if I should reveal the problem, but it was related to binary search trees. I wrote 4 test cases, varying from 0 to 10 nodes. I was rejected.
What are some guidelines to writing test cases for interviews?
(How big a case do interviewers expect? How many cases do interviewers expect? etc.)