# HG changeset patch
# User deba
# Date 1196178103 0
# Node ID 616c019215c4d60f92e6d37871da594932dabfb7
# Parent  05c0ba99cc276447efccd40ca8fca853092c9d58
Performance bug in Preflow
The initial relabeling moved each node to the lowest level
Doc bug fix

diff -r 05c0ba99cc27 -r 616c019215c4 lemon/dinitz_sleator_tarjan.h
--- a/lemon/dinitz_sleator_tarjan.h	Sun Nov 25 22:56:44 2007 +0000
+++ b/lemon/dinitz_sleator_tarjan.h	Tue Nov 27 15:41:43 2007 +0000
@@ -701,9 +701,10 @@
 
     /// @}
 
-    /// \name Query Functions
-    /// The result of the %Dijkstra algorithm can be obtained using these
-    /// functions.\n
+    /// \name Query Functions 
+    /// The result of the Dinitz-Sleator-Tarjan algorithm can be
+    /// obtained using these functions.
+    /// \n
     /// Before the use of these functions,
     /// either run() or start() must be called.
     
diff -r 05c0ba99cc27 -r 616c019215c4 lemon/edmonds_karp.h
--- a/lemon/edmonds_karp.h	Sun Nov 25 22:56:44 2007 +0000
+++ b/lemon/edmonds_karp.h	Tue Nov 27 15:41:43 2007 +0000
@@ -467,7 +467,7 @@
     /// @}
 
     /// \name Query Functions
-    /// The result of the %Dijkstra algorithm can be obtained using these
+    /// The result of the Edmonds-Karp algorithm can be obtained using these
     /// functions.\n
     /// Before the use of these functions,
     /// either run() or start() must be called.
diff -r 05c0ba99cc27 -r 616c019215c4 lemon/goldberg_tarjan.h
--- a/lemon/goldberg_tarjan.h	Sun Nov 25 22:56:44 2007 +0000
+++ b/lemon/goldberg_tarjan.h	Tue Nov 27 15:41:43 2007 +0000
@@ -103,13 +103,13 @@
   /// of the Goldberg's \ref Preflow "preflow" algorithm by using the \ref
   /// DynamicTree "dynamic tree" data structure of Sleator and Tarjan.
   /// 
-  /// The original preflow algorithm with \e "highest label" or \e
-  /// FIFO heuristic has \f$O(n^3)\f$ time complexity. The current
-  /// algorithm improved this complexity to
-  /// \f$O(nm\log(\frac{n^2}{m}))\f$. The algorithm builds limited
-  /// size dynamic trees on the residual graph, which can be used to
-  /// make multilevel push operations and gives a better bound on the
-  /// number of non-saturating pushes.
+  /// The original preflow algorithm with \e highest \e label
+  /// heuristic has \f$O(n^2\sqrt{e})\f$ or with \e FIFO heuristic has
+  /// \f$O(n^3)\f$ time complexity. The current algorithm improved
+  /// this complexity to \f$O(nm\log(\frac{n^2}{m}))\f$. The algorithm
+  /// builds limited size dynamic trees on the residual graph, which
+  /// can be used to make multilevel push operations and gives a
+  /// better bound on the number of non-saturating pushes.
   ///
   /// \param Graph The directed graph type the algorithm runs on.
   /// \param CapacityMap The capacity map type.
@@ -965,11 +965,12 @@
 
     /// @}
 
-    /// \name Query Functions
-    /// The result of the %Dijkstra algorithm can be obtained using these
-    /// functions.\n
-    /// Before the use of these functions,
-    /// either run() or start() must be called.
+    /// \name Query Functions 
+    /// The result of the Goldberg-Tarjan algorithm can be obtained
+    /// using these functions.
+    /// \n
+    /// Before the use of these functions, either run() or start() must
+    /// be called.
     
     ///@{
 
diff -r 05c0ba99cc27 -r 616c019215c4 lemon/preflow.h
--- a/lemon/preflow.h	Sun Nov 25 22:56:44 2007 +0000
+++ b/lemon/preflow.h	Tue Nov 27 15:41:43 2007 +0000
@@ -72,7 +72,7 @@
     ///
     /// \sa Elevator
     /// \sa LinkedElevator
-    typedef LinkedElevator<Graph, typename Graph::Node> Elevator;
+    typedef Elevator<Graph, typename Graph::Node> Elevator;
     
     /// \brief Instantiates an Elevator.
     ///
@@ -100,7 +100,7 @@
   /// directed graph. The preflow algorithms are the fastest known max
   /// flow algorithms. The current implementation use a mixture of the
   /// \e "highest label" and the \e "bound decrease" heuristics.
-  /// The worst case time complexity of the algorithm is \f$O(n^3)\f$.
+  /// The worst case time complexity of the algorithm is \f$O(n^2\sqrt{e})\f$.
   ///
   /// The algorithm consists from two phases. After the first phase
   /// the maximal flow value and the minimum cut can be obtained. The
@@ -407,6 +407,7 @@
       queue.push_back(_target);
       reached.set(_target, true);
       while (!queue.empty()) {
+	_level->initNewLevel();
 	std::vector<Node> nqueue;
 	for (int i = 0; i < int(queue.size()); ++i) {
 	  Node n = queue[i];
@@ -863,7 +864,7 @@
     /// @}
 
     /// \name Query Functions
-    /// The result of the %Dijkstra algorithm can be obtained using these
+    /// The result of the %Preflow algorithm can be obtained using these
     /// functions.\n
     /// Before the use of these functions,
     /// either run() or start() must be called.