+#ifdef DEBUG
+ if(is_dag()) {
+ cout << "find_shortest_path: DAG -> ok" << endl;
+ } else {
+ for(int e = 0; e < _nb_edges; e++) {
+ if(_edges[e].positivized_length < 0) abort();
+ }
+ cout << "find_shortest_path: All positivized_length are positive -> ok" << endl;
+ }
+#endif
+