Borderou de evaluare (job #293992)

Compilare: user.cpp: In function 'std::string simplify()': user.cpp:52:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] user.cpp: In function 'std::string make_rpm(std::string)': user.cpp:66:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] user.cpp: In function 'bool eval(std::string)': user.cpp:97:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]