Compilare: user.cpp: In function ‘int main()’: user.cpp:134:31: warning: ‘next_edge.Edge::index’ may be used uninitialized in this function [-Wmaybe-uninitialized] fout << next_edge.index << " " << next_edge.type << "\n"; ^ user.cpp:15:51: warning: ‘next_edge.Edge::type’ may be used uninitialized in this function [-Wmaybe-uninitialized] return node == e.node && index == e.index && type == e.type; ^ user.cpp:122:14: note: ‘next_edge.Edge::type’ was declared here Edge next_edge; ^ user.cpp:89:50: warning: ‘next_edge.Edge::node’ may be used uninitialized in this function [-Wmaybe-uninitialized] g[b].edges.erase(find(g[b].edges.begin(), g[b].edges.end(), edge_b)); ^ user.cpp:122:14: note: ‘next_edge.Edge::node’ was declared here Edge next_edge; ^