# HG changeset patch
# User marci
# Date 1095344847 0
# Node ID c19cf2007a7abfdf6c8c4bf15ab03af61455a859
# Parent  805963ea8654e8cb3fbead278aa6c975652c6d3b
more docs

diff -r 805963ea8654 -r c19cf2007a7a src/demo/sub_graph_wrapper_demo.cc
--- a/src/demo/sub_graph_wrapper_demo.cc	Thu Sep 16 14:01:36 2004 +0000
+++ b/src/demo/sub_graph_wrapper_demo.cc	Thu Sep 16 14:27:27 2004 +0000
@@ -2,6 +2,8 @@
 
 // Use a DIMACS max flow file as stdin.
 // sub_graph_wrapper_demo < dimacs_max_flow_file
+// This program computes a maximum number of disjoint shortest paths
+// between s and t.
 
 #include <iostream>
 #include <fstream>
@@ -46,16 +48,21 @@
   Dijkstra dijkstra(g, length);
   dijkstra.run(s);
 
+  // This map returns true exactly for those edges which are 
+  // tight w.r.t the length funcion and the potential 
+  // given by the dijkstra algorithm.
   typedef TightEdgeFilterMap<Graph, const Dijkstra::DistMap, LengthMap> 
     TightEdgeFilter;
   TightEdgeFilter tight_edge_filter(g, dijkstra.distMap(), length);
 
   ConstMap<Node, bool> const_true_map(true);
+  // This graph contains exaclty the tight edges.
   typedef SubGraphWrapper<Graph, ConstMap<Node, bool>, TightEdgeFilter> SubGW;
   SubGW gw(g, const_true_map, tight_edge_filter);
 
   ConstMap<Edge, int> const_1_map(1);
   Graph::EdgeMap<int> flow(g, 0);
+  // Max flow between s and t in the graph of tight edges.
   Preflow<SubGW, int, ConstMap<Edge, int>, Graph::EdgeMap<int> > 
     preflow(gw, s, t, const_1_map, flow);
   preflow.run();