From another post:
Hi here are some solutions for the 2004/2005 big oh questions
2004 question 1b)
algorithm A - O(n) as n increases by 10 the running time also increases by 10.
algorithm B - O(n2) (that's n squared) as n increases by 10 the running time increases by 10 squared (ie 100).
algorithm C - O(log n)(thats log to the base 10) the running time increases slowly. Running time T = 10 log n - 10.
When you see that the running time is increasing slowly it is most likely a log function.
2005 question 1a)
Algorithm A O(n) see A above
Algorithm B O(n log n) (thats log to the base 10) Running time T = 2n log n.
If you look at this algorithm you will notice that it is not quite O(n) nor is O(n squared). It is someting in between hence it most likey O(n log n). From this you can determine that T=2n log n.
regards
Lazarus