add connected blocks to verify partition tool

Author: N-Maas

mt-kahypar/partition/connected_components/CMakeLists.txt

@@ -2,3 +2,5 @@ set(ConnectedComponentsSources
         compute_components.cpp)
 
 target_sources(MtKaHyPar-Sources INTERFACE ${ConnectedComponentsSources})
+
+target_sources(MtKaHyPar-ToolsSources INTERFACE ${ConnectedComponentsSources})

tools/verify_partition.cc

@@ -35,6 +35,7 @@
 #include "mt-kahypar/datastructures/static_hypergraph.h"
 #include "mt-kahypar/datastructures/partitioned_hypergraph.h"
 #include "mt-kahypar/datastructures/connectivity_info.h"
+#include "mt-kahypar/partition/connected_components/compute_components.h"
 #include "mt-kahypar/partition/context.h"
 #include "mt-kahypar/partition/metrics.h"
 #include "mt-kahypar/io/hypergraph_factory.h"
@@ -100,6 +101,11 @@ int main(int argc, char* argv[]) {
     " - hmetis: hMETIS hypergraph file format\n"
     " - metis: METIS graph file format"
   )->default_str("hmetis");
+  app.add_option(
+    "--connected-blocks",
+    context.partition.connected_blocks,
+    "Ensure that the blocks of the resulting partition are connected"
+  )->capture_default_str();
   app.add_option(
     "-f,--fixed,--fixed-vertices",
     context.partition.fixed_vertex_filename,
@@ -150,6 +156,19 @@ int main(int argc, char* argv[]) {
     }
   }
 
+  // Check connected blocks
+  if ( context.partition.connected_blocks ) {
+    vec<vec<connected_components::ConnectedComponent>> components;
+    connected_components::compute_components_per_block(phg, context, components);
+
+    for ( PartitionID i = 0; i < context.partition.k; ++i ) {
+      if ( components[i].size() > 1 ) {
+        LOG << RED << "Block" << i << "has" << components[i].size() << "components and is therefore not connected" << END;
+        success = false;
+      }
+    }
+  }
+
   std::cout << "***********************" << context.partition.k
             << "-way Partition Result************************" << std::endl;
   std::cout << "cut =" << metrics::quality(phg, Objective::cut) << std::endl;