Compilare: main.cpp: In function 'int getNr()': main.cpp:24:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 24 | while (ptr<s.size() && isdigit (s[ptr])) | ~~~^~~~~~~~~ main.cpp: In function 'int rec()': main.cpp:33:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 33 | while (ptr<s.size() && s[ptr]!=')') | ~~~^~~~~~~~~