Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:20:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[nod].size();++i) ~^~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:64:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<sola.size();++i) ~^~~~~~~~~~~~ user.cpp:71:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<solb.size();++i) ~^~~~~~~~~~~~