# HG changeset patch
# User Peter Kovacs <kpeter@inf.elte.hu>
# Date 1376944554 7200
# Node ID b40c2bbb8da5210894426e3c4405b8a6d6d50d22
# Parent fb932bcfd803e4ed14c9d750d924a09eb230aadd
Fix division by zero error in case of empty graph (#474)
diff git a/lemon/network_simplex.h b/lemon/network_simplex.h
a

b


929  929  for (NodeIt n(_graph); n != INVALID; ++n, ++i) { 
930  930  _node_id[n] = i; 
931  931  } 
932   if (_arc_mixing) { 
 932  if (_arc_mixing && _node_num > 1) { 
933  933  // Store the arcs in a mixed order 
934  934  const int skip = std::max(_arc_num / _node_num, 3); 
935  935  int i = 0, j = 0; 
diff git a/test/min_cost_flow_test.cc b/test/min_cost_flow_test.cc
a

b


395  395  mcf3.upperMap(neg2_u); 
396  396  checkMcf(mcf3, mcf3.run(param), neg2_gr, neg2_l, neg2_u, neg2_c, neg2_s, 
397  397  mcf3.OPTIMAL, true, 300, test_str + "18", GEQ); 
 398  
 399  // Tests for empty graph 
 400  Digraph gr0; 
 401  MCF mcf0(gr0); 
 402  mcf0.run(param); 
 403  check(mcf0.totalCost() == 0, "Wrong total cost"); 
398  404  } 
399  405  
400  406  template < typename MCF, typename Param > 