Here's the problem. I'm creating a program that can allocate the optimal amount of sound files that can be fit in a limited space, i.e. I have 17 tracks that I have to allocate to a 90-minute cassette. I need to have the optimal allocation that I can do for Side A, in other words, the optimal group of tracks for that side.

I know there's a formula for that, unfortunately I can't remember and I can't find an online resource for the subject. Please help. Thanks.

Personally, the easiest way is to add up the track times which are displayed in iTunes, WMP and many others.

Yes, but the program has to automatically do that for me and determine which tracks will best fill the first side. It doesn't have to be the most number of files, but the one that will best utilize the limited space (in terms of seconds).

For example, in the 17 tracks, I can fit 8 tracks in the first side of a 90-min cassette (so each side can accommodate 45 mins) and will take up 44:45 minutes or 6 tracks that can take up 44:53. In my given scenario, the 6-track group is the optimal group since it's the one that fills it up closest to the limit.