Changeset 924:a80381c43760 in lemon-main

Timestamp:

02/28/11 10:19:34 (14 years ago)

Author:

Alpar Juttner <alpar@…>

Branch:

default

Parents:

922:9312d6c89d02 (diff), 923:30d5f950aa5f (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Phase:

public

Message:

Merge bugfix #414

Files:

• lemon/preflow.h (modified) (2 diffs)
• lemon/preflow.h (modified) (9 diffs)
• test/preflow_test.cc (modified) (2 diffs)
• test/preflow_test.cc (modified) (3 diffs)

lemon/preflow.h

@@ -544 +544 @@
           _flow->set(e, (*_capacity)[e]);
           (*_excess)[u] += rem;
-          if (u != _target && !_level->active(u)) {
-            _level->activate(u);
-          }
         }
       }
@@ -556 +553 @@
           _flow->set(e, 0);
           (*_excess)[v] += rem;
-          if (v != _target && !_level->active(v)) {
-            _level->activate(v);
-          }
-        }
-      }
+        }
+      }
+      for (NodeIt n(_graph); n != INVALID; ++n) 
+        if(n!=_source && n!=_target && _tolerance.positive((*_excess)[n]))
+          _level->activate(n);
+          
       return true;
     }

lemon/preflow.h

@@ -3 +3 @@
  * This file is a part of LEMON, a generic C++ optimization library.
  *
- * Copyright (C) 2003-2009
+ * Copyright (C) 2003-2010
  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
  * (Egervary Research Group on Combinatorial Optimization, EGRES).
@@ -53 +53 @@
     /// The type of the map that stores the flow values.
     /// It must meet the \ref concepts::ReadWriteMap "ReadWriteMap" concept.
+#ifdef DOXYGEN
+    typedef GR::ArcMap<Value> FlowMap;
+#else
     typedef typename Digraph::template ArcMap<Value> FlowMap;
+#endif
 
     /// \brief Instantiates a FlowMap.
@@ -68 +72 @@
     /// The elevator type used by Preflow algorithm.
     ///
-    /// \sa Elevator
-    /// \sa LinkedElevator
-    typedef LinkedElevator<Digraph, typename Digraph::Node> Elevator;
+    /// \sa Elevator, LinkedElevator
+#ifdef DOXYGEN
+    typedef lemon::Elevator<GR, GR::Node> Elevator;
+#else
+    typedef lemon::Elevator<Digraph, typename Digraph::Node> Elevator;
+#endif
 
     /// \brief Instantiates an Elevator.
@@ -96 +103 @@
   /// This class provides an implementation of Goldberg-Tarjan's \e preflow
   /// \e push-relabel algorithm producing a \ref max_flow
-  /// "flow of maximum value" in a digraph.
+  /// "flow of maximum value" in a digraph \ref clrs01algorithms,
+  /// \ref amo93networkflows, \ref goldberg88newapproach.
   /// The preflow algorithms are the fastest known maximum
-  /// flow algorithms. The current implementation use a mixture of the
+  /// flow algorithms. The current implementation uses a mixture of the
   /// \e "highest label" and the \e "bound decrease" heuristics.
   /// The worst case time complexity of the algorithm is \f$O(n^2\sqrt{e})\f$.
@@ -106 +114 @@
   /// second phase constructs a feasible maximum flow on each arc.
   ///
+  /// \warning This implementation cannot handle infinite or very large
+  /// capacities (e.g. the maximum value of \c CAP::Value).
+  ///
   /// \tparam GR The type of the digraph the algorithm runs on.
   /// \tparam CAP The type of the capacity map. The default map
   /// type is \ref concepts::Digraph::ArcMap "GR::ArcMap<int>".
+  /// \tparam TR The traits class that defines various types used by the
+  /// algorithm. By default, it is \ref PreflowDefaultTraits
+  /// "PreflowDefaultTraits<GR, CAP>".
+  /// In most cases, this parameter should not be set directly,
+  /// consider to use the named template parameters instead.
 #ifdef DOXYGEN
   template <typename GR, typename CAP, typename TR>
@@ -258 +274 @@
     /// able to automatically created by the algorithm (i.e. the
     /// digraph and the maximum level should be passed to it).
-    /// However an external elevator object could also be passed to the
+    /// However, an external elevator object could also be passed to the
     /// algorithm with the \ref elevator(Elevator&) "elevator()" function
     /// before calling \ref run() or \ref init().
@@ -372 +388 @@
     }
 
-    /// \brief Sets the tolerance used by algorithm.
-    ///
-    /// Sets the tolerance used by algorithm.
+    /// \brief Sets the tolerance used by the algorithm.
+    ///
+    /// Sets the tolerance object used by the algorithm.
+    /// \return <tt>(*this)</tt>
     Preflow& tolerance(const Tolerance& tolerance) {
       _tolerance = tolerance;
@@ -382 +399 @@
     /// \brief Returns a const reference to the tolerance.
     ///
-    /// Returns a const reference to the tolerance.
+    /// Returns a const reference to the tolerance object used by
+    /// the algorithm.
     const Tolerance& tolerance() const {
       return _tolerance;
@@ -390 +408 @@
     /// The simplest way to execute the preflow algorithm is to use
     /// \ref run() or \ref runMinCut().\n
-    /// If you need more control on the initial solution or the execution,
-    /// first you have to call one of the \ref init() functions, then
+    /// If you need better control on the initial solution or the execution,
+    /// you have to call one of the \ref init() functions first, then
     /// \ref startFirstPhase() and if you need it \ref startSecondPhase().
 

test/preflow_test.cc

@@ -157 +157 @@
 }
 
+void initFlowTest()
+{
+  DIGRAPH_TYPEDEFS(SmartDigraph);
+  
+  SmartDigraph g;
+  SmartDigraph::ArcMap<int> cap(g),iflow(g);
+  Node s=g.addNode(); Node t=g.addNode();
+  Node n1=g.addNode(); Node n2=g.addNode();
+  Arc a;
+  a=g.addArc(s,n1); cap[a]=20; iflow[a]=20;
+  a=g.addArc(n1,n2); cap[a]=10; iflow[a]=0;
+  a=g.addArc(n2,t); cap[a]=20; iflow[a]=0;
+
+  Preflow<SmartDigraph> pre(g,cap,s,t);
+  pre.init(iflow);
+  pre.startFirstPhase();
+  check(pre.flowValue() == 10, "The incorrect max flow value.");
+  check(pre.minCut(s), "Wrong min cut (Node s).");
+  check(pre.minCut(n1), "Wrong min cut (Node n1).");
+  check(!pre.minCut(n2), "Wrong min cut (Node n2).");
+  check(!pre.minCut(t), "Wrong min cut (Node t).");
+}
+
+
 int main() {
 
@@ -247 +271 @@
         "The max flow value or the three min cut values are incorrect.");
 
+  initFlowTest();
+  
   return 0;
 }

test/preflow_test.cc

@@ -3 +3 @@
  * This file is a part of LEMON, a generic C++ optimization library.
  *
- * Copyright (C) 2003-2009
+ * Copyright (C) 2003-2010
  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
  * (Egervary Research Group on Combinatorial Optimization, EGRES).
@@ -96 +96 @@
   const PreflowType& const_preflow_test = preflow_test;
 
+  const PreflowType::Elevator& elev = const_preflow_test.elevator();
+  preflow_test.elevator(const_cast<PreflowType::Elevator&>(elev));
+  PreflowType::Tolerance tol = const_preflow_test.tolerance();
+  preflow_test.tolerance(tol);
+
   preflow_test
     .capacityMap(cap)
@@ -114 +119 @@
   b = const_preflow_test.minCut(n);
   const_preflow_test.minCutMap(cut);
-  
+
   ignore_unused_variable_warning(fm);
 }