Compilare: user.cpp: In function ‘void insert(const std::pair<int, int>&)’: user.cpp:19:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0;i<hashul[key].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:56:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0;j<hashul[i].size();j++) ^ user.cpp:63:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0;i<sol.size();i++) ^