Compilare: user.cpp: In function ‘void prelucrare(std::string)’: user.cpp:14:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(s[i]!=')' && i<s.size()) ^ user.cpp: In function ‘int main()’: user.cpp:36:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<s.size();i++) ^