Compilare: user.cpp: In function ‘int main()’: user.cpp:19:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<v[a%x].size();++j) ^ user.cpp:25:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(j==v[a%x].size()) ^ user.cpp:32:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<v[i].size();++j) ^