change TC to only operate on lower or upper triangle, add return to c…

…onnected components

data/tc_test.csv

@@ -6,10 +6,10 @@ A,E,1
 B,C,1
 B,D,1
 B,E,1
+B,F,1
 C,D,1
-E,C,1
+C,E,1
 D,E,1
-B,F,1
 E,F,1
 E,G,1
 F,H,1

include/graph/algorithm/connected_components.hpp

@@ -88,8 +88,8 @@ void kosaraju(G&&        g,        // graph
 template <adjacency_list      G,
           random_access_range Component>
 requires random_access_range<vertex_range_t<G>> && integral<vertex_id_t<G>>
-void connected_components(G&&        g,        // graph
-                          Component& component // out: connected component assignment
+size_t connected_components(G&&        g,        // graph
+                            Component& component // out: connected component assignment
 ) {
   size_t            N(size(vertices(g)));
   std::vector<bool> visited(N, false);
@@ -114,6 +114,7 @@ void connected_components(G&&        g,        // graph
     }
     ++cid;
   }
+  return cid;
 }
 
 } // namespace graph

include/graph/algorithm/tc.hpp

@@ -42,10 +42,6 @@ size_t triangle_count(G&& g) {
     auto                         ie = end(edges(g, uid));
     while (i != ie) {
       auto&& [vid, uv] = *i;
-      if (vid < uid) {
-        ++i;
-        continue;
-      }
       graph::incidence_iterator<G> j(g, vid);
 
       auto je = end(edges(g, vid));

tests/tc_tests.cpp

@@ -19,8 +19,8 @@ TEST_CASE("triangle counting test", "[tc]") {
   init_console();
 
   using G  = routes_vol_graph_type;
-  auto&& g = load_ordered_graph<G>(TEST_DATA_ROOT_DIR "tc_test.csv", name_order_policy::alphabetical, true);
+  auto&& g = load_ordered_graph<G>(TEST_DATA_ROOT_DIR "tc_test.csv", name_order_policy::alphabetical);
 
   size_t triangles = graph::triangle_count(g);
   REQUIRE(triangles == 11);
-}
+}