I'm learning computer science in a college and I'm taking the course 'Algorithms 1'. Some of its content is "graph theory".
I wonder whether it belongs to this site or to Stack Overflow?
I would suggest the following guidelines for algorithms, graph theory, and Theory of Computation questions:
If your question can only be answered by referring to or writing actual code, it belongs on stackoverflow.
If your question can only be answered by referring to or writing pseudocode, then it belongs anywhere.
If your question can be answered without looking at and without writing any code, then it belongs on Math.SE.
If your question is about proving an algorithm is correct or runs in a certain time, it belongs on CS.SE or Math.SE
If your question uses the word "prove" in any other context it belongs on Math.SE
Code questions (e.g. "How do I write Dijkstra's algorithm in C++?") are not welcome here.
Math questions (e.g. "Is this graph guaranteed a circuit?"--or something similar) are welcome here, so long as you explain your thoughts on the problem.
Code and math questions can go either way. In general, though, if the question is mainly about the math behind the code, post it here. If it's about implementation, post it on SO.
The fuzzier boundary is between Math.SE and CS.SE (and CSTheory.SE).