diff -r d8475431bbbb -r 8e85e6bbefdf demo/min_route.cc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/demo/min_route.cc	Mon May 23 04:48:14 2005 +0000
@@ -0,0 +1,114 @@
+#include <iostream>
+#include <fstream>
+
+#include <lemon/smart_graph.h>
+#include <lemon/dijkstra.h>
+#include <lemon/maps.h>
+#include <lemon/xy.h>
+#include <lemon/graph_reader.h>
+
+#include <lemon/time_measure.h>
+
+#include <cmath>
+
+
+using namespace lemon;
+
+template <typename CoordMap>
+class PotentialMap {
+public:
+  typedef double Value;
+  typedef typename CoordMap::Key Key;
+
+  PotentialMap(const CoordMap& _coord, const xy<double>& _target)
+    : coord(_coord), target(_target) {}
+
+  double operator[](const Key& node) const {
+    return std::sqrt((coord[node].x - target.x) * (coord[node].x - target.x) + 
+		     (coord[node].y - target.y) * (coord[node].y - target.y));
+  }
+private:
+  const CoordMap& coord;
+  xy<double> target;
+};
+
+template <typename Graph, typename LengthMap, typename PotentialMap>
+class ReducedLengthMap {
+public:
+  typedef double Value;
+  typedef typename LengthMap::Key Key;
+
+  ReducedLengthMap(const Graph& _graph, const LengthMap& _length, 
+		   const PotentialMap& _pot) 
+    : graph(_graph), length(_length), pot(_pot) {}
+
+  Value operator[](const Key& edge) const {
+    return length[edge] - (pot[graph.source(edge)] - pot[graph.target(edge)]);
+  }
+
+private:
+  const Graph& graph;
+  const LengthMap& length;
+  const PotentialMap& pot;
+};
+
+int main() {
+  typedef SmartGraph Graph;
+
+  typedef Graph::Edge Edge;
+  typedef Graph::Node Node;
+  typedef Graph::EdgeIt EdgeIt;
+  typedef Graph::NodeIt NodeIt;
+  typedef Graph::EdgeMap<double> LengthMap;
+  typedef Graph::NodeMap<xy<double> > CoordMap;
+
+  SmartGraph graph;
+
+  std::ifstream is("route.lgf");
+  GraphReader<Graph> reader(is, graph);
+  
+  CoordMap coord(graph);
+  XMap<CoordMap> xcoord = xMap(coord);
+  reader.readNodeMap("coordinates_x", xcoord);
+  YMap<CoordMap> ycoord = yMap(coord);
+  reader.readNodeMap("coordinates_y", ycoord);
+
+  LengthMap length(graph);
+  reader.readEdgeMap("length", length);
+
+  Node source, target;
+  reader.readNode("source", source);
+  reader.readNode("target", target);
+
+  reader.run();
+
+  {
+    Timer timer;
+    Dijkstra<Graph, LengthMap> dijkstra(graph, length);
+    dijkstra.init();
+    dijkstra.addSource(source);
+    dijkstra.start(target);
+
+    std::cout << dijkstra.dist(target) << std::endl;
+    std::cout << timer << std::endl;
+  }
+  {
+    Timer timer;
+    typedef PotentialMap<CoordMap> Potential;
+    Potential potential(coord, coord[target]);
+
+    typedef ReducedLengthMap<Graph, LengthMap, Potential> ReducedLength;
+    ReducedLength reduced(graph, length, potential);
+
+    Dijkstra<Graph, ReducedLength> dijkstra(graph, reduced);
+
+    dijkstra.init();
+    dijkstra.addSource(source);
+    dijkstra.start(target);
+  
+    std::cout << dijkstra.dist(target) + potential[source] << std::endl;
+    std::cout << timer << std::endl;
+  }
+
+  return 0;
+}