I’m just working on a problem where I want to find polygons in a user-defined graph. So far, your algorithm description was the best I found. However, I am having problems finding an algorithm for “turning right” (assuming I have a node with an incoming edge and multiple outgoing edges). Maybe that’s just because I’m not using the right search terms (I am neither very familiar with this whole graph topic, nor am I a native english speaker). It would be great if you could help me here or provide me some pointers to valuable sites. Thanks a lot!