Graph help using petgraph

I have been working on a graph question find the start and end points in a graph. I have managed to get pass the first test case using dfs. But there next test case has a cycle inside it. Here is what the edges look like (0,3) (1,2) (3,2) (2,4) (4,3) (2,5)
Start points: 0, 1 Endpoints: 5. What would be the best approach for this? Not look for a answer more so a hint in the right direction. Thanks for any help.

Which version of dfs are you using, e.g. the Dfs in petgraph::visit - Rust
or depth_first_search in petgraph::visit - Rust the latter one allows greater flexibility with cyclic graphs, and both the examples for it contain graphs with cycles.