Clearly this is a fun problem! I did this a few years ago too[1] and thought it might be a useful service, I made a naive solution in JS for my needs that takes

Clearly this is a fun problem! I did this a few years ago too[1] and thought it might be a useful service, I made a naive solution in JS for my needs that takes a Boolean matrix specifying who can't give to another! I even made a code golf challenge for it! [1]: https://gist.github.com/dom111/4a4ede77f44c46c5d968 https://gist.github.com/dom111/4a4ede77f44c46c5d968