Compilare: user.cpp: In function ‘void read()’: user.cpp:44:18: warning: unused variable ‘x’ [-Wunused-variable] for(int i=1, x, y, cost1, cost2; i<=m; ++i) ^ user.cpp:44:21: warning: unused variable ‘y’ [-Wunused-variable] for(int i=1, x, y, cost1, cost2; i<=m; ++i) ^ user.cpp: In function ‘void bfs()’: user.cpp:77:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<G[x].size(); ++i) ^