Changeset 224:5bc1c83257f8 in lemon-0.x for src/work/alpar/dijkstra/dijkstra.h

Timestamp:

03/21/04 15:59:51 (21 years ago)

Author:

Alpar Juttner

Branch:

default

Phase:

public

Convert:

svn:c9d7d8f5-90d6-0310-b91f-818b3a526b0e/lemon/trunk@321

Message:

Some doc added

File:

• src/work/alpar/dijkstra/dijkstra.h (modified) (6 diffs)

src/work/alpar/dijkstra/dijkstra.h

@@ -33 +33 @@
   
   //Alpar: Changed the order of the parameters
+  
+  ///Dijkstra algorithm class.
+
+  ///This class provides an efficient implementation of Dijkstra algorithm.
+  ///The edge lengths are passed to the algorithm using a
+  ///\ref ReadMapSkeleton "readable map",
+  ///so it is easy to change it to any kind of length.
+  ///
+  ///The type of the length is determined by the \c ValueType of the length map.
+  ///
+  ///It is also posible to change the underlying priority heap.
+  ///
+  ///\param Graph The graph type the algorithm runs on.
+  ///\param LengthMap This read-only EdgeMap determines the
+  ///lengths of the edges. It is read once for each edge, so the map
+  ///may involve in relatively time consuming process to compute the edge
+  ///length if it is necessary.
+  ///\param Heap The heap type used by the Dijkstra
+  ///algorithm. The default
+  ///is using \ref BinHeap "binary heap".
   template <typename Graph,
             typename LengthMap=typename Graph::EdgeMap<int>,
-            typename Heap=FibHeap<typename Graph::Node,
+            typename Heap=BinHeap<typename Graph::Node,
                                   typename LengthMap::ValueType, 
                                   typename Graph::NodeMap<int> > >
@@ -41 +61 @@
   public:
     typedef typename LengthMap::ValueType ValueType;
+    typedef typename Graph::NodeMap<Edge> PredMap;
+    typedef typename Graph::NodeMap<Node> PredNodeMap;
+    typedef typename Graph::NodeMap<ValueType> DistMap;
 
   private:
@@ -50 +73 @@
     const Graph& G;
     const LengthMap& length;
-    typedef typename Graph::NodeMap<Edge> PredMap;
     PredMap predecessor;
     //In place of reach:
-    typedef typename Graph::NodeMap<Node> PredNodeMap;
     PredNodeMap pred_node;
-    typedef typename Graph::NodeMap<ValueType> DistMap;
     DistMap distance;
     //I don't like this:
@@ -73 +93 @@
     void run(Node s);
     
+    ///The distance of a node from the source.
+
+    ///Returns the distance of a node from the source.
+    ///\pre \ref run() must be called before using this function.
+    ///\warning If node \c v in unreachable from \c s the return value
+    ///of this funcion is undefined.
     ValueType dist(Node v) const { return distance[v]; }
+    ///Returns the edges of the shortest path tree.
+
+    ///For a node \c v it returns the last edge of the shortest path
+    ///from \c s to \c v or INVALID if \c v is unreachable from \c s.
+    ///\pre \ref run() must be called before using this function.
     Edge pred(Node v) const { return predecessor[v]; }
+    ///Returns the nodes of the shortest paths.
+
+    ///For a node \c v it returns the last but one node of the shortest path
+    ///from \c s to \c v or INVALID if \c v is unreachable from \c s.
+    ///\pre \ref run() must be called before using this function.
     Node predNode(Node v) const { return pred_node[v]; }
     
+    ///Returns a reference to the NodeMap of distances.
+
+    ///\pre \ref run() must be called before using this function.
+    ///
     const DistMap &distMap() const { return distance;}
+    ///Returns a reference to the shortest path tree map.
+
+    ///Returns a reference to the NodeMap of the edges of the
+    ///shortest path tree.
+    ///\pre \ref run() must be called before using this function.
     const PredMap &predMap() const { return predecessor;}
+    ///Returns a reference to the map of nodes of  shortest paths.
+
+    ///Returns a reference to the NodeMap of the last but one nodes of the
+    ///shortest paths.
+    ///\pre \ref run() must be called before using this function.
     const PredNodeMap &predNodeMap() const { return pred_node;}
 
     //    bool reached(Node v) { return reach[v]; }
-    ///\warning \c s is not reached!
+
+    ///Chech if a node is reachable from \c s.
+
+    ///Returns \c true if \c v is reachable from \c s.
+    ///\warning \c s is reported to be unreached!
+    ///\todo Is this what we want?
+    ///\pre \ref run() must be called before using this function.
     ///
     bool reached(Node v) { return G.valid(predecessor[v]); }
@@ -89 +145 @@
   
 
-  // IMPLEMENTATIONS
-
+  // **********************************************************************
+  //  IMPLEMENTATIONS
+  // **********************************************************************
+
+  ///Runs Dijkstra algorithm from node \c s.
+
+  ///This method runs the Dijkstra algorithm from node \c s in order to
+  ///compute the
+  ///shortest path to each node. The algorithm computes
+  ///- The shortest path tree.
+  ///- The distance of each node.
   template <typename Graph, typename LengthMap, typename Heap >
   void Dijkstra<Graph,LengthMap,Heap>::run(Node s) {
@@ -97 +162 @@
     for ( G.first(u) ; G.valid(u) ; G.next(u) ) {
       predecessor.set(u,INVALID);
+      pred_node.set(u,INVALID);
       // If a node is unreacheable, then why should be the dist=0?
       // distance.set(u,0);