Compilare: user.cpp: In function ‘int main()’: user.cpp:66:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<comp.size();i++) ^ user.cpp:68:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<comp[i].size();j++) fout<<comp[i][j]<<" "; ^