Compilare: main.cpp: In function 'int evaluate(std::string)': main.cpp:29:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 29 | for(int i=0;i<s.size();i++){ | ~^~~~~~~~~ main.cpp:36:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 36 | while(i<s.size() and isdigit(s[i])){ | ~^~~~~~~~~ main.cpp: In function 'int applyOp(int, int, char)': main.cpp:23:1: warning: control reaches end of non-void function [-Wreturn-type] 23 | } | ^