Compilare: main.cpp: In function 'int main()': main.cpp:79:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 79 | while (k < s.size() && cif(s[k])) | ~~^~~~~~~~~~ main.cpp:106:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 106 | while (k < op.size()) | ~~^~~~~~~~~~~ main.cpp:104:14: warning: unused variable 'rez' [-Wunused-variable] 104 | bool rez = 0; | ^~~ main.cpp: In function 'char applyop(char, char, char, int)': main.cpp:43:1: warning: control reaches end of non-void function [-Wreturn-type] 43 | } | ^ main.cpp: In function 'int level(char)': main.cpp:52:1: warning: control reaches end of non-void function [-Wreturn-type] 52 | } | ^