Compilare: user.cpp: In function ‘int getInt(std::__cxx11::string, int&)’: user.cpp:23:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(isdigit(s[poz])&&poz<s.size()) { ~~~^~~~~~~~~ user.cpp: In function ‘int calculate_expression(std::__cxx11::string, int&)’: user.cpp:46:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(poz>=s.size()) ~~~^~~~~~~~~~ user.cpp:61:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(poz>=s.size()) ~~~^~~~~~~~~~ user.cpp:67:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(s[poz]!=')'&&poz<s.size()) { ~~~^~~~~~~~~ user.cpp: In function ‘int readAndCompute(std::__cxx11::string, int&)’: user.cpp:124:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(poz<s.size()&&s[poz]!=')') { ~~~^~~~~~~~~ user.cpp: In function ‘int compute(int, char, int)’: user.cpp:35:1: warning: control reaches end of non-void function [-Wreturn-type] } ^