Verbose output in cerr.

diff --git a/mtp.cc b/mtp.cc
index 9fa61aa..8f37fd6 100644 (file)
--- a/mtp.cc
+++ b/mtp.cc
@@ -181,7 +181,7 @@ void Graph::find_shortest_path(Vertex **front, Vertex **new_front) {
     }
   }
 #ifdef VERBOSE
-  cout << "residual_error " << residual_error << endl;
+  cerr << "residual_error " << residual_error << endl;
 #endif
 
   for(int v = 0; v < nb_vertices; v++) {