Compilare: user.cpp: In function ‘void df(int, int)’: user.cpp:35:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<G[k].size();++i) { ^ user.cpp:48:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<G[k].size();++i) ^ user.cpp:34:21: warning: variable ‘nm2’ set but not used [-Wunused-but-set-variable] int nm, vm=INF, nm2, vm2=INF; ^ user.cpp: In function ‘int main()’: user.cpp:60:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<G[x].size();++i) ^ user.cpp: In function ‘void df(int, int)’: user.cpp:35:29: warning: ‘nm’ may be used uninitialized in this function [-Wmaybe-uninitialized] for(int i=0;i<G[k].size();++i) { ^