feat: add topological sorting

[fffzlfk]

No description provided.

[erfan-khadem]

Hi!
Based on this comment, it was decided we can have some code (I implemented it in #294, not merged yet) that converts between BTreeMap representation and a Vec based one.

As I am reading your code, it would be more performant, smaller, and more readable if you change it to use a Vec based (compressed) adjacency matrix representation.

Even if (for understandable reasons) you don't want to do it that way, I have a suggestion:
representing the list of adjacent vertices for each vertex v in the graph as a separate BTreeMap is kind of overkill. You can easily get more performance by replacing BTreeMap<V, BTreeMap ...> with BTreeMap<V, Vec<(V, E)>>

One minor thing: You can remove Debug trait bound for your vertex type.

[fffzlfk]

Hi! Based on this comment, it was decided we can have some code (I implemented it in #294, not merged yet) that converts between BTreeMap representation and a Vec based one.

As I am reading your code, it would be more performant, smaller, and more readable if you change it to use a Vec based (compressed) adjacency matrix representation.

Even if (for understandable reasons) you don't want to do it that way, I have a suggestion: representing the list of adjacent vertices for each vertex v in the graph as a separate BTreeMap is kind of overkill. You can easily get more performance by replacing BTreeMap<V, BTreeMap ...> with BTreeMap<V, Vec<(V, E)>>

One minor thing: You can remove Debug trait bound for your vertex type.

Thanks for the review, I have done as you suggested

[siriak]

LGTM, thanks!