The other important reason to use a library is that if someone improves the algorithm someday, you can benefit for nothing more than installing and testing the

The other important reason to use a library is that if someone improves the algorithm someday, you can benefit for nothing more than installing and testing the new version of the library. I remember this also being the case for Constraint Satisfaction Problem (CSP) algorithms in AI. If you can formulate your problem as a CSP and feed it to a library, you automatically benefit from future improvements in the field of CSP solvers.