Oops, first post on Mathematica, simply because I dont use it for research, I simply love Matlab and C++, due to their popularity and easy-to-use. However, good news for Mathematica fans, here I found an excellent Mathematica package named "The Combinatorica Project", which is a package written in 1989 by Steve Skiena for exercising computational discrete mathematics.

here is the introductory page and downloading link, have fun and enjoy new week.
http://www.cs.uiowa.edu/~sriram/Combinatorica/
Unclear about this post? Asking questions and receiving answers.