diff -r 4338e4280f67 -r 04733359bac2 src/demo/lp_maxflow_demo.cc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/demo/lp_maxflow_demo.cc	Fri Apr 15 20:46:18 2005 +0000
@@ -0,0 +1,68 @@
+#include<lemon/lp_glpk.h>
+#include<lemon/graph_reader.h>
+#include<lemon/list_graph.h>
+
+using namespace lemon;
+
+template<class G,class C>
+double maxFlow(const G &g,const C &cap,typename G::Node s,typename G::Node t)
+{
+  LpGlpk lp;
+  
+  typedef G Graph;
+  typedef typename G::Node Node;
+  typedef typename G::NodeIt NodeIt;
+  typedef typename G::Edge Edge;
+  typedef typename G::EdgeIt EdgeIt;
+  typedef typename G::OutEdgeIt OutEdgeIt;
+  typedef typename G::InEdgeIt InEdgeIt;
+  
+  typename G::template EdgeMap<LpGlpk::Col> x(g);
+  lp.addColSet(x);
+  
+  for(EdgeIt e(g);e!=INVALID;++e) {
+    lp.colUpperBound(x[e],cap[e]);
+    lp.colLowerBound(x[e],0);
+  }
+
+  for(NodeIt n(g);n!=INVALID;++n) if(n!=s&&n!=t) {
+    LpGlpk::Expr ex;
+    for(InEdgeIt  e(g,n);e!=INVALID;++e) ex+=x[e];
+    for(OutEdgeIt e(g,n);e!=INVALID;++e) ex-=x[e];
+    lp.addRow(ex==0);
+  }
+  {
+    LpGlpk::Expr ex;
+    for(InEdgeIt  e(g,t);e!=INVALID;++e) ex+=x[e];
+    for(OutEdgeIt e(g,t);e!=INVALID;++e) ex-=x[e];
+    lp.setObj(ex);
+  }
+  lp.max();
+
+  lp.presolver(true);
+  
+  lp.messageLevel(3);
+
+  lp.solve();
+
+  return lp.primalValue();
+}
+
+int main() 
+{
+  ListGraph g;
+  ListGraph::Node s;
+  ListGraph::Node t;
+  
+  ListGraph::EdgeMap<double> cap(g);
+  
+  GraphReader<ListGraph> reader(std::cin,g);
+  reader.addNode("source",s).addNode("target",t)
+    .addEdgeMap("capacity",cap).run();
+  
+  // std::ifstream file("../test/preflow_");
+//   readDimacs(file, g, cap, s, t);
+
+  std::cout << "Max flow value = " << maxFlow(g,cap,s,t) << std::endl;
+
+}