Compilare: user.cpp: In function ‘void parseLine(std::string)’: user.cpp:24:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < line.size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:81:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < values[keys[0]].size(); ++i) ^