1.1 --- a/lemon/network_simplex.h	Mon Jul 07 11:23:41 2014 +0200
     1.2 +++ b/lemon/network_simplex.h	Mon Jul 07 15:40:12 2014 +0200
     1.3 @@ -936,7 +936,7 @@
     1.4        for (NodeIt n(_graph); n != INVALID; ++n, ++i) {
     1.5          _node_id[n] = i;
     1.6        }
     1.7 -      if (_arc_mixing) {
     1.8 +      if (_arc_mixing && _node_num > 1) {
     1.9          // Store the arcs in a mixed order
    1.10          const int skip = std::max(_arc_num / _node_num, 3);
    1.11          int i = 0, j = 0;