How to know the index of HALO nodes?

Hi, folks,

I can successfully use METIS 5.1.0 API to partition a graph file into the desired number of parts in Fortran codes. But how could I know which nodes are HALO/overlap nodes (nodes in the separators between any 2 neighbouring parts) after the METIS_PartGraphKway API is called? Could you tell me how to handle this case? I really want to know which nodes in the graph are internal nodes and which nodes in the graph are the HALO/overlap nodes after partitioning. Here a node in the graph is equivalent to a vetex mentioned in the METIS manual.

I look forward to hearing from you and thanks in advance.