Function iter

code/graph/bipartite_mvc.test.cpp:16–18

    }
    bipartite_graph g(n,m);
    iter(it,es) {
      g.add_edge(it->first, it->second);
    }
    int sz = g.maximum_matching();
    vector<int> res = mvc_bipartite(g);
    set<int> cover;