Merge pull request #421 from murraycu/develop-murrayc-examples-modern-cpp-attempt2

examples: C++11: Some use of range-based for loops

Author: jeremy-murphy

example/cuthill_mckee_ordering.cpp

@@ -57,8 +57,8 @@ int main(int, char*[])
         Pair(6, 7) }; // g-h
 
     Graph G(10);
-    for (int i = 0; i < 14; ++i)
-        add_edge(edges[i].first, edges[i].second, G);
+    for (auto const& edge : edges)
+        add_edge(edge.first, edge.second, G);
 
     graph_traits< Graph >::vertex_iterator ui, ui_end;
 
@@ -79,8 +79,8 @@ int main(int, char*[])
             get(vertex_degree, G));
         cout << "Reverse Cuthill-McKee ordering starting at: " << s << endl;
         cout << "  ";
-        for (auto i = inv_perm.begin(); i != inv_perm.end(); ++i)
-            cout << index_map[*i] << " ";
+        for (auto const& vertex : inv_perm)
+            cout << index_map[vertex] << " ";
         cout << endl;
 
         for (size_type c = 0; c != inv_perm.size(); ++c)
@@ -98,8 +98,8 @@ int main(int, char*[])
             get(vertex_degree, G));
         cout << "Reverse Cuthill-McKee ordering starting at: " << s << endl;
         cout << "  ";
-        for (auto i = inv_perm.begin(); i != inv_perm.end(); ++i)
-            cout << index_map[*i] << " ";
+        for (auto const& vertex : inv_perm)
+            cout << index_map[vertex] << " ";
         cout << endl;
 
         for (size_type c = 0; c != inv_perm.size(); ++c)
@@ -118,8 +118,8 @@ int main(int, char*[])
 
         cout << "Reverse Cuthill-McKee ordering:" << endl;
         cout << "  ";
-        for (auto i = inv_perm.begin(); i != inv_perm.end(); ++i)
-            cout << index_map[*i] << " ";
+        for (auto const& vertex : inv_perm)
+            cout << index_map[vertex] << " ";
         cout << endl;
 
         for (size_type c = 0; c != inv_perm.size(); ++c)

example/edge-connectivity.cpp

@@ -136,13 +136,13 @@ typename graph_traits< VertexListGraph >::degree_size_type edge_connectivity(
     }
 
     std::vector< bool > in_S_star(num_vertices(g), false);
-    for (auto si = S_star.begin(); si != S_star.end(); ++si)
-        in_S_star[*si] = true;
+    for (auto const& vertex : S_star.begin())
+        in_S_star[vertex] = true;
     degree_size_type c = 0;
-    for (auto si = S_star.begin(); si != S_star.end(); ++si)
+    for (auto const& vertex : S_star.begin())
     {
         typename graph_traits< VertexListGraph >::out_edge_iterator ei, ei_end;
-        for (boost::tie(ei, ei_end) = out_edges(*si, g); ei != ei_end; ++ei)
+        for (boost::tie(ei, ei_end) = out_edges(vertex, g); ei != ei_end; ++ei)
             if (!in_S_star[target(*ei, g)])
             {
                 *disconnecting_set++ = *ei;
@@ -170,9 +170,9 @@ int main()
     auto attr_map = get(vertex_attribute, g);
 
     std::cout << "The disconnecting set is {";
-    for (auto i = disconnecting_set.begin(); i != disconnecting_set.end(); ++i)
-        std::cout << "(" << attr_map[source(*i, g)]["label"] << ","
-                  << attr_map[target(*i, g)]["label"] << ") ";
+    for (auto const& edge : disconnecting_set)
+        std::cout << "(" << attr_map[source(edge, g)]["label"] << ","
+                  << attr_map[target(edge, g)]["label"] << ") ";
     std::cout << "}." << std::endl;
     return EXIT_SUCCESS;
 }

example/king_ordering.cpp

@@ -98,8 +98,8 @@ int main(int, char*[])
             get(vertex_degree, G), get(vertex_index, G));
         cout << "King ordering starting at: " << s << endl;
         cout << "  ";
-        for (auto i = inv_perm.begin(); i != inv_perm.end(); ++i)
-            cout << index_map[*i] << " ";
+        for (auto const& vertex : inv_perm)
+            cout << index_map[vertex] << " ";
         cout << endl;
 
         for (size_type c = 0; c != inv_perm.size(); ++c)
@@ -118,8 +118,8 @@ int main(int, char*[])
 
         cout << "King ordering:" << endl;
         cout << "  ";
-        for (auto i = inv_perm.begin(); i != inv_perm.end(); ++i)
-            cout << index_map[*i] << " ";
+        for (auto const& vertex : inv_perm)
+            cout << index_map[vertex] << " ";
         cout << endl;
 
         for (size_type c = 0; c != inv_perm.size(); ++c)

example/kruskal-telephone.cpp

@@ -46,14 +46,14 @@ int main()
 
     auto weight = get(edge_weight, g);
     int total_weight = 0;
-    for (size_type e = 0; e < mst.size(); ++e)
-        total_weight += get(weight, mst[e]);
+    for (auto const& edge : mst)
+        total_weight += get(weight, edge);
     std::cout << "total weight: " << total_weight << std::endl;
 
     typedef graph_traits< Graph >::vertex_descriptor Vertex;
-    for (size_type i = 0; i < mst.size(); ++i)
+    for (auto const& edge : mst)
     {
-        auto u = source(mst[i], g), v = target(mst[i], g);
+        auto u = source(edge, g), v = target(edge, g);
         edge_attr_map[edge(u, v, g_dot).first]["color"] = "black";
     }
     std::ofstream out("figs/telephone-mst-kruskal.dot");

example/matching_example.cpp

@@ -74,8 +74,8 @@ int main()
 
     std::cout << "In the following graph:" << std::endl << std::endl;
 
-    for (auto itr = ascii_graph.begin(); itr != ascii_graph.end(); ++itr)
-        std::cout << *itr << std::endl;
+    for (auto const& str : ascii_graph)
+        std::cout << str << std::endl;
 
     std::cout << std::endl
               << "Found a matching of size " << matching_size(g, &mate[0])

example/topo-sort1.cpp

@@ -28,9 +28,8 @@ int main()
     topological_sort(g, std::front_inserter(topo_order),
         vertex_index_map(identity_property_map()));
 
-    int n = 1;
-    for (auto i = topo_order.begin(); i != topo_order.end(); ++i, ++n)
-        std::cout << tasks[*i] << std::endl;
+    for (auto const& vertex : topo_order)
+        std::cout << tasks[vertex] << std::endl;
 
     return EXIT_SUCCESS;
 }

example/topo-sort2.cpp

@@ -35,9 +35,8 @@ int main()
     topological_sort(g, std::front_inserter(topo_order),
         vertex_index_map(identity_property_map()));
 
-    int n = 1;
-    for (auto i = topo_order.begin(); i != topo_order.end(); ++i, ++n)
-        std::cout << tasks[*i] << std::endl;
+    for (auto const& vertex : topo_order)
+        std::cout << tasks[vertex] << std::endl;
 
     return EXIT_SUCCESS;
 }