Compilare: main.cpp: In function 'int evaluare(std::string)': main.cpp:47:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 47 | for (int i = 0; i<u_l.size(); i++) { | ~^~~~~~~~~~~ main.cpp:53:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 53 | while (i<u_l.size() && isdigit(u_l[i])) { | ~^~~~~~~~~~~ main.cpp: In function 'int exec_operatie(int, char, int)': main.cpp:18:1: warning: control reaches end of non-void function [-Wreturn-type] 18 | } | ^