It is entirely up to the task description. There are tasks where you are expected to reimplement a particular algorithm, and there are tasks where the point is to demonstrate how neatly you can do something in your language by any means available.
If you use a library, use the {{libheader|your language here}} template to index the usage.
Re: Can libs be used or should code snippet be atomic
Date: 2009-08-04 02:00 (UTC)If you use a library, use the {{libheader|your language here}} template to index the usage.