Ticket #81: mod_dijkstra_demo_9b052679a797.patch

demo/digraph.lgf

@@ -9 +9 @@
 6
 7
 @arcs
-                label capacity
-0       1       0         16
-0       2       1         12
-0       3       2         20
-1       2       3         10
-1       4       4         10
-1       5       5         13
-2       3       6         10
-2       4       7         8
-2       6       8         8
-5       3       9         20
-3       6       10        25
-4       7       11        15
-5       7       12        15
-6       7       13        18
+                label   length
+0       1       0       10
+0       2       1       20
+0       3       2       30
+1       2       3       5
+1       4       4       16
+1       5       5       10
+2       3       6       12
+2       4       7       15
+2       6       8       20
+3       6       10      8
+4       7       11      20
+5       3       9       5
+5       7       12      25
+6       7       13      10
 @attributes
 source 0
 target 7

demo/dijkstra_demo.cc

@@ -29 +29 @@
 
 #include <iostream>
 #include <lemon/list_graph.h>
+#include <lemon/lgf_reader.h>
 #include <lemon/dijkstra.h>
 
 using namespace lemon;
 
 int main (int, char*[])
 {
-  // Convenient type definitions
+  // Type definitions
   typedef ListDigraph Digraph;
   typedef Digraph::Node Node;
-  typedef Digraph::Arc Arc;
   typedef Digraph::ArcMap<int> LengthMap;
 
-  // Create a directed graph and a length map
+  // Read a digraph with arc lengths form 'digraph.lgf'
   Digraph g;
-
-  Node s=g.addNode();
-  Node v2=g.addNode();
-  Node v3=g.addNode();
-  Node v4=g.addNode();
-  Node v5=g.addNode();
-  Node t=g.addNode();
-
-  Arc s_v2=g.addArc(s, v2);
-  Arc s_v3=g.addArc(s, v3);
-  Arc v2_v4=g.addArc(v2, v4);
-  Arc v2_v5=g.addArc(v2, v5);
-  Arc v3_v5=g.addArc(v3, v5);
-  Arc v4_t=g.addArc(v4, t);
-  Arc v5_t=g.addArc(v5, t);
-
   LengthMap len(g);
-
-  len.set(s_v2, 10);
-  len.set(s_v3, 10);
-  len.set(v2_v4, 5);
-  len.set(v2_v5, 8);
-  len.set(v3_v5, 5);
-  len.set(v4_t, 8);
-  len.set(v5_t, 8);
+  Node s, t;
+  digraphReader("digraph.lgf", g).
+    arcMap("length", len).
+    node("source", s).
+    node("target", t).
+    run();
 
   std::cout << "This program is a simple demo of the LEMON Dijkstra class."
             << std::endl;
   std::cout << "We calculate the shortest path from node s to node t in a digraph."
             << std::endl << std::endl;
 
+  // Print the IDs of s and t
   std::cout << "The id of s is " << g.id(s) << ", "
             << "the id of t is " << g.id(t) << "." << std::endl;
 

demo/lgf_demo.cc

@@ -40 +40 @@
 
 int main() {
   SmartDigraph g;
-  SmartDigraph::ArcMap<int> cap(g);
+  SmartDigraph::ArcMap<int> len(g);
   SmartDigraph::Node s, t;
   
   try {
     digraphReader("digraph.lgf", g). // read the directed graph into g
-      arcMap("capacity", cap).       // read the 'capacity' arc map into cap
+      arcMap("length", len).         // read the 'length' arc map into len
       node("source", s).             // read 'source' node to s
       node("target", t).             // read 'target' node to t
       run();
@@ -61 +61 @@
   std::cout << "We can write it to the standard output:" << std::endl;
 
   digraphWriter(std::cout, g).     // write g to the standard output
-    arcMap("capacity", cap).       // write cap into 'capacity'
+    arcMap("weight", len).         // write len into 'weight'
     node("source", s).             // write s to 'source'
     node("target", t).             // write t to 'target'
     run();