Deleted by OP, but reopened while deleted, undeleted
[NB: I have now cast a vote to undelete.]
Please reopen undelete How to find all systems of distinct representatives using i.e. Hopcroft–Karp algorithm?How to find all systems of distinct representatives using i.e. Hopcroft–Karp algorithm?
Recently a Question about finding all maximal matchings of a bipartite graph was closed (placed "on-hold") as off-topic in part because it was a cross-post of a StackOverflow post and in part because it concerned how an existing program that finds one maximal matching could be modified to find all of them.
So far so good, as I also voted to close.
Then the same user posted this new Question, How to find all systems of distinct representatives using i.e. Hopcroft–Karp algorithm?How to find all systems of distinct representatives using i.e. Hopcroft–Karp algorithm? While substantively the topic is nearly identical, it asks about modifying that algorithm, not about modifying some code. The problem of finding all maximal matchings in bipartite graphs is studied in the literature, esp. by Takeaki Uno (see this 1997 paper and some later papers).
With this perhaps subtle change I think the new Question is on-topic for Math.SE, and I've voted to reopen. In general I think we should avoid "closing as duplicate" when the target has no (good) answers and the underlying problem is truly on-topic here.