We use an arc "array" in the graph structure, but not all arc indexes
correspond to real topological arcs. We must be careful when iterating
through all arcs, and check if they are enabled before making operations
on them.
Changelog-None: askrene: fix bug, not all arcs exists
Signed-off-by: Lagrang3 <lagrang3@protonmail.com>
Add a new function to compute a MCF using a more general description of
the problem. I call it mcf_refinement because it can start with a
feasible flow (though this is not necessary) and adapt it to achieve
optimality.
Changelog-None: askrene: add a MCF refinement
Signed-off-by: Lagrang3 <lagrang3@protonmail.com>
