Compilare: user.cpp: In function ‘void add(int)’: user.cpp:40:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<G[node].size();++i) ^ user.cpp:51:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<G[node].size();++i) ^ user.cpp: In function ‘void write()’: user.cpp:91:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<sol.size();++i) ^