Changeset 268:f4eb1ae59b50 in lemon-0.x for src/work

Timestamp:

03/30/04 19:47:51 (21 years ago)

Author:

marci

Branch:

default

Phase:

public

Convert:

svn:c9d7d8f5-90d6-0310-b91f-818b3a526b0e/lemon/trunk@374

Message:

blocking flows

Location:

src/work

Files:

• edmonds_karp.h (modified) (1 diff)
• marci/edmonds_karp_demo.cc (modified) (3 diffs)

src/work/edmonds_karp.h

@@ -433 +433 @@
     }
 
-//     template<typename MutableGraph> bool augmentOnBlockingFlow1() {      
-//       bool _augment=false;
-
-//       AugGraph res_graph(*G, *flow, *capacity);
-
-//       //bfs for distances on the residual graph
-//       typedef typename AugGraph::NodeMap<bool> ReachedMap;
-//       BfsIterator5< AugGraph, ReachedMap > bfs(res_graph);
-//       bfs.pushAndSetReached(s);
-//       typename AugGraph::NodeMap<int> dist(res_graph); //filled up with 0's
-
-//       //F will contain the physical copy of the residual graph
-//       //with the set of edges which areon shortest paths
-//       MutableGraph F;
-//       typename AugGraph::NodeMap<typename MutableGraph::Node> 
-//      res_graph_to_F(res_graph);
-//       for(typename AugGraph::NodeIt n=res_graph.template first<typename AugGraph::NodeIt>(); res_graph.valid(n); res_graph.next(n)) {
-//      res_graph_to_F.set(n, F.addNode());
-//       }
-//       typename MutableGraph::Node sF=res_graph_to_F.get(s);
-//       typename MutableGraph::Node tF=res_graph_to_F.get(t);
-//       typename MutableGraph::EdgeMap<AugEdge> original_edge(F);
-//       typename MutableGraph::EdgeMap<Number> residual_capacity(F);
-
-//       while ( !bfs.finished() ) { 
-//      AugOutEdgeIt e=bfs;
-//      if (res_graph.valid(e)) {
-//        if (bfs.isBNodeNewlyReached()) {
-//          dist.set(res_graph.head(e), dist.get(res_graph.tail(e))+1);
-//          typename MutableGraph::Edge f=F.addEdge(res_graph_to_F.get(res_graph.tail(e)), res_graph_to_F.get(res_graph.head(e)));
-//          original_edge.update();
-//          original_edge.set(f, e);
-//          residual_capacity.update();
-//          residual_capacity.set(f, res_graph.free(e));
-//        } else {
-//          if (dist.get(res_graph.head(e))==(dist.get(res_graph.tail(e))+1)) {
-//            typename MutableGraph::Edge f=F.addEdge(res_graph_to_F.get(res_graph.tail(e)), res_graph_to_F.get(res_graph.head(e)));
-//            original_edge.update();
-//            original_edge.set(f, e);
-//            residual_capacity.update();
-//            residual_capacity.set(f, res_graph.free(e));
-//          }
-//        }
-//      }
-//      ++bfs;
-//       } //computing distances from s in the residual graph
-
-//       bool __augment=true;
-
-//       while (__augment) {
-//      __augment=false;
-//      //computing blocking flow with dfs
-//      typedef typename TrivGraphWrapper<MutableGraph>::NodeMap<bool> BlockingReachedMap;
-//      DfsIterator5< TrivGraphWrapper<MutableGraph>/*, typename MutableGraph::OutEdgeIt*/, BlockingReachedMap > dfs(F);
-//      typename MutableGraph::NodeMap<typename MutableGraph::Edge> pred(F);
-//      pred.set(sF, typename MutableGraph::Edge(INVALID));
-//      //invalid iterators for sources
-
-//      typename MutableGraph::NodeMap<Number> free(F);
-
-//      dfs.pushAndSetReached(sF);      
-//      while (!dfs.finished()) {
-//        ++dfs;
-//        if (F.valid(typename MutableGraph::OutEdgeIt(dfs))) {
-//          if (dfs.isBNodeNewlyReached()) {
-//            typename MutableGraph::Node v=F.aNode(dfs);
-//            typename MutableGraph::Node w=F.bNode(dfs);
-//            pred.set(w, dfs);
-//            if (F.valid(pred.get(v))) {
-//              free.set(w, std::min(free.get(v), residual_capacity.get(dfs)));
-//            } else {
-//              free.set(w, residual_capacity.get(dfs)); 
-//            }
-//            if (w==tF) { 
-//              __augment=true; 
-//              _augment=true;
-//              break; 
-//            }
+    template<typename MutableGraph> bool augmentOnBlockingFlow1() {      
+      bool _augment=false;
+
+      AugGraph res_graph(gw, *flow, *capacity);
+
+      //bfs for distances on the residual graph
+      typedef typename AugGraph::NodeMap<bool> ReachedMap;
+      BfsIterator5< AugGraph, ReachedMap > bfs(res_graph);
+      bfs.pushAndSetReached(s);
+      typename AugGraph::NodeMap<int> dist(res_graph); //filled up with 0's
+
+      //F will contain the physical copy of the residual graph
+      //with the set of edges which areon shortest paths
+      MutableGraph F;
+      typename AugGraph::NodeMap<typename MutableGraph::Node> 
+        res_graph_to_F(res_graph);
+      for(typename AugGraph::NodeIt n=res_graph.template first<typename AugGraph::NodeIt>(); res_graph.valid(n); res_graph.next(n)) {
+        res_graph_to_F.set(n, F.addNode());
+      }
+      typename MutableGraph::Node sF=res_graph_to_F.get(s);
+      typename MutableGraph::Node tF=res_graph_to_F.get(t);
+      typename MutableGraph::EdgeMap<AugEdge> original_edge(F);
+      typename MutableGraph::EdgeMap<Number> residual_capacity(F);
+
+      while ( !bfs.finished() ) { 
+        AugOutEdgeIt e=bfs;
+        if (res_graph.valid(e)) {
+          if (bfs.isBNodeNewlyReached()) {
+            dist.set(res_graph.head(e), dist.get(res_graph.tail(e))+1);
+            typename MutableGraph::Edge f=F.addEdge(res_graph_to_F.get(res_graph.tail(e)), res_graph_to_F.get(res_graph.head(e)));
+            original_edge.update();
+            original_edge.set(f, e);
+            residual_capacity.update();
+            residual_capacity.set(f, res_graph.free(e));
+          } else {
+            if (dist.get(res_graph.head(e))==(dist.get(res_graph.tail(e))+1)) {
+              typename MutableGraph::Edge f=F.addEdge(res_graph_to_F.get(res_graph.tail(e)), res_graph_to_F.get(res_graph.head(e)));
+              original_edge.update();
+              original_edge.set(f, e);
+              residual_capacity.update();
+              residual_capacity.set(f, res_graph.free(e));
+            }
+          }
+        }
+        ++bfs;
+      } //computing distances from s in the residual graph
+
+      bool __augment=true;
+
+      while (__augment) {
+        __augment=false;
+        //computing blocking flow with dfs
+        typedef typename TrivGraphWrapper<MutableGraph>::NodeMap<bool> BlockingReachedMap;
+        DfsIterator5< TrivGraphWrapper<MutableGraph>/*, typename MutableGraph::OutEdgeIt*/, BlockingReachedMap > dfs(F);
+        typename MutableGraph::NodeMap<typename MutableGraph::Edge> pred(F);
+        pred.set(sF, typename MutableGraph::Edge(INVALID));
+        //invalid iterators for sources
+
+        typename MutableGraph::NodeMap<Number> free(F);
+
+        dfs.pushAndSetReached(sF);      
+        while (!dfs.finished()) {
+          ++dfs;
+          if (F.valid(typename MutableGraph::OutEdgeIt(dfs))) {
+            if (dfs.isBNodeNewlyReached()) {
+              typename MutableGraph::Node v=F.aNode(dfs);
+              typename MutableGraph::Node w=F.bNode(dfs);
+              pred.set(w, dfs);
+              if (F.valid(pred.get(v))) {
+                free.set(w, std::min(free.get(v), residual_capacity.get(dfs)));
+              } else {
+                free.set(w, residual_capacity.get(dfs)); 
+              }
+              if (w==tF) { 
+                __augment=true; 
+                _augment=true;
+                break; 
+              }
               
-//          } else {
-//            F.erase(typename MutableGraph::OutEdgeIt(dfs));
-//          }
-//        } 
-//      }
-
-//      if (__augment) {
-//        typename MutableGraph::Node n=tF;
-//        Number augment_value=free.get(tF);
-//        while (F.valid(pred.get(n))) { 
-//          typename MutableGraph::Edge e=pred.get(n);
-//          res_graph.augment(original_edge.get(e), augment_value); 
-//          n=F.tail(e);
-//          if (residual_capacity.get(e)==augment_value) 
-//            F.erase(e); 
-//          else 
-//            residual_capacity.set(e, residual_capacity.get(e)-augment_value);
-//        }
-//      }
+            } else {
+              F.erase(typename MutableGraph::OutEdgeIt(dfs));
+            }
+          } 
+        }
+
+        if (__augment) {
+          typename MutableGraph::Node n=tF;
+          Number augment_value=free.get(tF);
+          while (F.valid(pred.get(n))) { 
+            typename MutableGraph::Edge e=pred.get(n);
+            res_graph.augment(original_edge.get(e), augment_value); 
+            n=F.tail(e);
+            if (residual_capacity.get(e)==augment_value) 
+              F.erase(e); 
+            else 
+              residual_capacity.set(e, residual_capacity.get(e)-augment_value);
+          }
+        }
         
-//       }
+      }
             
-//       return _augment;
-//     }
+      return _augment;
+    }
+
 //     bool augmentOnBlockingFlow2() {
 //       bool _augment=false;

src/work/marci/edmonds_karp_demo.cc

@@ -122 +122 @@
   }
 
+  {
+    //std::cout << "SmartGraph..." << std::endl;
+    typedef TrivGraphWrapper<const Graph> GW;
+    GW gw(G);
+    std::cout << "edmonds karp demo (physical blocking flow 1 augmentation)..." << std::endl;
+    GW::EdgeMap<int> flow(G); //0 flow
+
+    Timer ts;
+    ts.reset();
+
+    typedef GW::EdgeMapWrapper< Graph::EdgeMap<int>, int > EMW;
+    EMW cw(cap);
+    MaxFlow<GW, int, GW::EdgeMap<int>, EMW > max_flow_test(gw, s, t, flow, cw);
+    int i=0;
+    while (max_flow_test.augmentOnBlockingFlow1<MutableGraph>()) { 
+//     for(EdgeIt e=G.template first<EdgeIt>(); e.valid(); ++e) { 
+//       std::cout<<"("<<G.tail(e)<< "-"<<flow.get(e)<<"->"<<G.head(e)<<") ";
+//     }
+//     std::cout<<std::endl;
+      ++i; 
+    }
+
+//   std::cout << "maximum flow: "<< std::endl;
+//   for(EdgeIt e=G.first<EdgeIt>(); e.valid(); ++e) { 
+//     std::cout<<"("<<G.tail(e)<< "-"<<flow.get(e)<<"->"<<G.head(e)<<") ";
+//   }
+//   std::cout<<std::endl;
+    std::cout << "elapsed time: " << ts << std::endl;
+    std::cout << "number of augmentation phases: " << i << std::endl; 
+    std::cout << "flow value: "<< max_flow_test.flowValue() << std::endl;
+  }
+
 //   {
-//     //std::cout << "SmartGraph..." << std::endl;
-//     std::cout << "edmonds karp demo (physical blocking flow 1 augmentation)..." << std::endl;
+//     std::cout << "edmonds karp demo (on-the-fly blocking flow augmentation)..." << std::endl;
 //     Graph::EdgeMap<int> flow(G); //0 flow
 
@@ -132 +163 @@
 //     MaxFlow<Graph, int, Graph::EdgeMap<int>, Graph::EdgeMap<int> > max_flow_test(G, s, t, flow, cap);
 //     int i=0;
-//     while (max_flow_test.augmentOnBlockingFlow1<MutableGraph>()) { 
+//     while (max_flow_test.augmentOnBlockingFlow2()) { 
 // //     for(EdgeIt e=G.template first<EdgeIt>(); e.valid(); ++e) { 
 // //       std::cout<<"("<<G.tail(e)<< "-"<<flow.get(e)<<"->"<<G.head(e)<<") ";
@@ -150 +181 @@
 //   }
 
-//   {
-//     std::cout << "edmonds karp demo (on-the-fly blocking flow augmentation)..." << std::endl;
-//     Graph::EdgeMap<int> flow(G); //0 flow
-
-//     Timer ts;
-//     ts.reset();
-
-//     MaxFlow<Graph, int, Graph::EdgeMap<int>, Graph::EdgeMap<int> > max_flow_test(G, s, t, flow, cap);
-//     int i=0;
-//     while (max_flow_test.augmentOnBlockingFlow2()) { 
-// //     for(EdgeIt e=G.template first<EdgeIt>(); e.valid(); ++e) { 
-// //       std::cout<<"("<<G.tail(e)<< "-"<<flow.get(e)<<"->"<<G.head(e)<<") ";
-// //     }
-// //     std::cout<<std::endl;
-//       ++i; 
-//     }
-
-// //   std::cout << "maximum flow: "<< std::endl;
-// //   for(EdgeIt e=G.first<EdgeIt>(); e.valid(); ++e) { 
-// //     std::cout<<"("<<G.tail(e)<< "-"<<flow.get(e)<<"->"<<G.head(e)<<") ";
-// //   }
-// //   std::cout<<std::endl;
-//     std::cout << "elapsed time: " << ts << std::endl;
-//     std::cout << "number of augmentation phases: " << i << std::endl; 
-//     std::cout << "flow value: "<< max_flow_test.flowValue() << std::endl;
-//   }
-
   {
     typedef TrivGraphWrapper<const Graph> GW;