Compilare: user.cpp: In function ‘std::pair<int, int> coeficienti(std::__cxx11::string)’: user.cpp:22:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(it<s.size()) ~~^~~~~~~~~ user.cpp:39:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(ok==0 and issemn(s[it])==0 and it!=s.size()) ~~^~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:78:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<ecuatie.size();j++) ~^~~~~~~~~~~~~~~ user.cpp:75:13: warning: unused variable ‘n’ [-Wunused-variable] int n=0,m=0; ^ user.cpp:75:17: warning: unused variable ‘m’ [-Wunused-variable] int n=0,m=0; ^