Changeset 133:0631992fe7a1 in lemon-0.x for src/work/edmonds_karp.hh

Timestamp:

02/27/04 13:39:15 (20 years ago)

Author:

marci

Branch:

default

Phase:

public

Convert:

svn:c9d7d8f5-90d6-0310-b91f-818b3a526b0e/lemon/trunk@180

Message:

Dinits blocking flow added to edmonds_karp_demo.hh.

File:

• src/work/edmonds_karp.hh (modified) (11 diffs)

src/work/edmonds_karp.hh

@@ -7 +7 @@
 
 #include <bfs_iterator.hh>
-#include <time_measure.h>
+//#include <time_measure.h>
 
 namespace hugo {
@@ -282 +282 @@
     public:
       EdgeIt() : out_or_in(1) { } 
+      //EdgeIt(const EdgeIt& e) : G(e.G), flow(e.flow), capacity(e.capacity), out(e.out), in(e.in), out_or_in(e.out_or_in) { }
       Number free() const { 
         if (out_or_in) { 
@@ -298 +299 @@
         }
       }
+      void print() { 
+        if (out_or_in) {
+          std::cout << "out "; 
+          if (out.valid()) 
+            std::cout << G->id(G->tail(out)) << "--"<< G->id(out) <<"->"<< G->id(G->head(out)); 
+          else 
+            std::cout << "invalid"; 
+        }
+        else {
+          std::cout << "in "; 
+          if (in.valid()) 
+            std::cout << G->id(G->head(in)) << "<-"<< G->id(in) <<"--"<< G->id(G->tail(in)); 
+          else 
+            std::cout << "invalid"; 
+        }
+        std::cout << std::endl;
+      }
     };
 
@@ -309 +327 @@
         flow=&_flow;
         capacity=&_capacity;
-        out=/*resG->*/G->template first<OldOutEdgeIt>(v);
+        //out=/*resG->*/G->template first<OldOutEdgeIt>(v);
+        G->getFirst(out, v);
         while( out.valid() && !(free()>0) ) { ++out; }
         if (!out.valid()) {
           out_or_in=0;
-          in=/*resG->*/G->template first<OldInEdgeIt>(v);
+          //in=/*resG->*/G->template first<OldInEdgeIt>(v);
+          G->getFirst(in, v);
           while( in.valid() && !(free()>0) ) { ++in; }
         }
@@ -325 +345 @@
           if (!out.valid()) {
             out_or_in=0;
-            in=/*resG->*/G->template first<OldInEdgeIt>(v);
+            G->getFirst(in, v); //=/*resG->*/G->template first<OldInEdgeIt>(v);
             while( in.valid() && !(free()>0) ) { ++in; }
           }
@@ -336 +356 @@
     };
 
+    class EachEdgeIt : public EdgeIt {
+      typename Graph::EachNodeIt v;
+    public:
+      EachEdgeIt() { }
+      //EachEdgeIt(const EachEdgeIt& e) : EdgeIt(e), v(e.v) { }
+      EachEdgeIt(const Graph& _G, FlowMap& _flow, const CapacityMap& _capacity) { 
+        G=&_G;
+        flow=&_flow;
+        capacity=&_capacity;
+        out_or_in=1;
+        G->getFirst(v);
+        if (v.valid()) G->getFirst(out, v); else out=OldOutEdgeIt();
+        while (out.valid() && !(free()>0) ) { ++out; }
+        while (v.valid() && !out.valid()) { 
+          ++v; 
+          if (v.valid()) G->getFirst(out, v); 
+          while (out.valid() && !(free()>0) ) { ++out; }
+        }
+        if (!out.valid()) {
+          out_or_in=0;
+          G->getFirst(v);
+          if (v.valid()) G->getFirst(in, v); else in=OldInEdgeIt();
+          while (in.valid() && !(free()>0) ) { ++in; }
+          while (v.valid() && !in.valid()) { 
+            ++v; 
+            if (v.valid()) G->getFirst(in, v); 
+            while (in.valid() && !(free()>0) ) { ++in; }
+          }
+        }
+      }
+      EachEdgeIt& operator++() { 
+        if (out_or_in) {
+          ++out;
+          while (out.valid() && !(free()>0) ) { ++out; }
+          while (v.valid() && !out.valid()) { 
+            ++v; 
+            if (v.valid()) G->getFirst(out, v); 
+            while (out.valid() && !(free()>0) ) { ++out; }
+          }
+          if (!out.valid()) {
+            out_or_in=0;
+            G->getFirst(v);
+            if (v.valid()) G->getFirst(in, v); else in=OldInEdgeIt();
+            while (in.valid() && !(free()>0) ) { ++in; }
+            while (v.valid() && !in.valid()) { 
+              ++v; 
+              if (v.valid()) G->getFirst(in, v); 
+              while (in.valid() && !(free()>0) ) { ++in; }
+            }  
+          }
+        } else {
+          ++in;
+          while (in.valid() && !(free()>0) ) { ++in; }
+          while (v.valid() && !in.valid()) { 
+            ++v; 
+            if (v.valid()) G->getFirst(in, v); 
+            while (in.valid() && !(free()>0) ) { ++in; }
+          }
+        }
+        return *this;
+      }
+    };
+
     void getFirst(OutEdgeIt& e, NodeIt v) const { 
       e=OutEdgeIt(G, v, flow, capacity); 
+    }
+    void getFirst(EachEdgeIt& e) const { 
+      e=EachEdgeIt(G, flow, capacity); 
     }
     void getFirst(EachNodeIt& v) const { G.getFirst(v); }
@@ -402 +488 @@
     //typedef typename AugGraph::NodeMap<bool> ReachedMap;
     //typename AugGraph::NodeMap<AugEdgeIt> pred; 
-    //typename AugGraph::NodeMap<int> free;
+    //typename AugGraph::NodeMap<Number> free;
   public:
     MaxFlow(const Graph& _G, NodeIt _s, NodeIt _t, FlowMap& _flow, const CapacityMap& _capacity) : 
@@ -408 +494 @@
       //res_graph(G, flow, capacity), pred(res_graph), free(res_graph) 
       { }
-    bool augment() {
+    bool augmentOnShortestPath() {
       AugGraph res_graph(G, flow, capacity);
       bool _augment=false;
@@ -420 +506 @@
       //pred.set(s, AugEdgeIt());
       
-      typename AugGraph::NodeMap<int> free(res_graph);
+      typename AugGraph::NodeMap<Number> free(res_graph);
         
       //searching for augmenting path
@@ -452 +538 @@
       return _augment;
     }
-    bool augmentWithBlockingFlow() {
-      BfsIterator4< Graph, OutEdgeIt, typename Graph::NodeMap<bool> > bfs(G);
+    template<typename MutableGraph> bool augmentOnBlockingFlow() {
+      bool _augment=false;
+
+      AugGraph res_graph(G, flow, capacity);
+
+      typedef typename AugGraph::NodeMap<bool> ReachedMap;
+      BfsIterator4< AugGraph, AugOutEdgeIt, ReachedMap > bfs(res_graph);
+
       bfs.pushAndSetReached(s);
-      typename Graph::NodeMap<int> dist(G); //filled up with 0's
+      typename AugGraph::NodeMap<int> dist(res_graph); //filled up with 0's
       while ( !bfs.finished() ) { 
-        OutEdgeIt e=OutEdgeIt(bfs);
+        AugOutEdgeIt e=AugOutEdgeIt(bfs);
         if (e.valid() && bfs.isBNodeNewlyReached()) {
-          dist.set(G.head(e), dist.get(G.tail(e))+1);
-          //NodeIt v=res_graph.tail(e);
-          //NodeIt w=res_graph.head(e);
-          //pred.set(w, e);
-          //if (pred.get(v).valid()) {
-          //  free.set(w, std::min(free.get(v), e.free()));
-          //} else {
-          //  free.set(w, e.free()); 
-          //}
-          //if (res_graph.head(e)==t) { _augment=true; break; }
+          dist.set(res_graph.head(e), dist.get(res_graph.tail(e))+1);
         }
         
         ++bfs;
-      } //end of searching augmenting path
-
-      double pre_time_copy=currTime();
-      typedef Graph MutableGraph;
+      } //computing distances from s in the residual graph
+
       MutableGraph F;
-      typename Graph::NodeMap<NodeIt> G_to_F(G);
-      for(typename Graph::EachNodeIt n=G.template first<typename Graph::EachNodeIt>(); n.valid(); ++n) {
-        G_to_F.set(n, F.addNode());
-      }
-      for(typename Graph::EachEdgeIt e=G.template first<typename Graph::EachEdgeIt>(); e.valid(); ++e) {
-        if (dist.get(G.head(e))==dist.get(G.tail(e))+1) {
-          F.addEdge(G_to_F.get(G.tail(e)), G_to_F.get(G.head(e)));
-        }
-      }
-      double post_time_copy=currTime();
-      std::cout << "copy time: " << post_time_copy-pre_time_copy << " sec"<< std::endl; 
-
-      return 0;
+      typename AugGraph::NodeMap<NodeIt> res_graph_to_F(res_graph);
+      for(typename AugGraph::EachNodeIt n=res_graph.template first<typename AugGraph::EachNodeIt>(); n.valid(); ++n) {
+        res_graph_to_F.set(n, F.addNode());
+      }
+      
+      typename MutableGraph::NodeIt sF=res_graph_to_F.get(s);
+      typename MutableGraph::NodeIt tF=res_graph_to_F.get(t);
+
+      typename MutableGraph::EdgeMap<AugEdgeIt> original_edge(F);
+      typename MutableGraph::EdgeMap<Number> free_on_edge(F);
+
+      //Making F to the graph containing the edges of the residual graph 
+      //which are in some shortest paths
+      for(typename AugGraph::EachEdgeIt e=res_graph.template first<typename AugGraph::EachEdgeIt>(); e.valid(); ++e) {
+        if (dist.get(res_graph.head(e))==dist.get(res_graph.tail(e))+1) {
+          typename MutableGraph::EdgeIt 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);
+          free_on_edge.update();
+          free_on_edge.set(f, e.free());
+        } 
+      }
+
+      bool __augment=true;
+
+      while (__augment) {
+        __augment=false;
+        //computing blocking flow with dfs
+        typedef typename MutableGraph::NodeMap<bool> BlockingReachedMap;
+        DfsIterator4< MutableGraph, typename MutableGraph::OutEdgeIt, BlockingReachedMap > dfs(F);
+        typename MutableGraph::NodeMap<EdgeIt> pred(F); //invalid iterators
+        typename MutableGraph::NodeMap<Number> free(F);
+
+        dfs.pushAndSetReached(sF);      
+        while (!dfs.finished()) {
+          ++dfs;
+          if (typename MutableGraph::OutEdgeIt(dfs).valid()) {
+            //std::cout << "OutEdgeIt: " << dfs; 
+            //std::cout << " aNode: " << F.aNode(dfs); 
+            //std::cout << " bNode: " << F.bNode(dfs) << " ";
+          
+            typename MutableGraph::NodeIt v=F.aNode(dfs);
+            typename MutableGraph::NodeIt w=F.bNode(dfs);
+            pred.set(w, dfs);
+            if (pred.get(v).valid()) {
+              free.set(w, std::min(free.get(v), free_on_edge.get(dfs)));
+            } else {
+              free.set(w, free_on_edge.get(dfs)/*original_edge.get(dfs).free()*/); 
+            }
+            if (w==tF) { 
+              //std::cout << "AUGMENTATION"<<std::endl;
+              __augment=true; 
+              _augment=true;
+              break; 
+            }
+          } else { 
+            //std::cout << "OutEdgeIt: " << "invalid"; 
+            //std::cout << " aNode: " << dfs.aNode(); 
+            //std::cout << " bNode: " << "invalid" << " ";
+          }
+          if (dfs.isBNodeNewlyReached()) { 
+            //std::cout << "bNodeIsNewlyReached ";
+          } else { 
+            //std::cout << "bNodeIsNotNewlyReached ";
+            if (typename MutableGraph::OutEdgeIt(dfs).valid()) {
+              //std::cout << "DELETE ";
+              F.erase(typename MutableGraph::OutEdgeIt(dfs));
+            }
+          } 
+          //if (dfs.isANodeExamined()) { 
+            //std::cout << "aNodeIsExamined ";
+            //} else { 
+            //std::cout << "aNodeIsNotExamined ";
+            //} 
+          //std::cout<<std::endl;
+        }
+
+        if (__augment) {
+          typename MutableGraph::NodeIt n=tF;
+          Number augment_value=free.get(tF);
+          while (pred.get(n).valid()) { 
+            typename MutableGraph::EdgeIt e=pred.get(n);
+            original_edge.get(e).augment(augment_value); 
+            n=F.tail(e);
+            F.erase(e);
+          }
+        }
+
+      }
+            
+      return _augment;
     }
     void run() {
       //int num_of_augmentations=0;
-      while (augment()) { 
+      while (augmentOnShortestPath()) { 
+        //while (augmentOnBlockingFlow<MutableGraph>()) { 
+        //std::cout << ++num_of_augmentations << " ";
+        //std::cout<<std::endl;
+      } 
+    }
+    template<typename MutableGraph> void run() {
+      //int num_of_augmentations=0;
+      //while (augmentOnShortestPath()) { 
+        while (augmentOnBlockingFlow<MutableGraph>()) { 
         //std::cout << ++num_of_augmentations << " ";
         //std::cout<<std::endl;
@@ -600 +768 @@
       //filled up with invalid iterators
       
-      typename AugGraph::NodeMap<int> free(res_graph);
+      typename AugGraph::NodeMap<Number> free(res_graph);
         
       //searching for augmenting path