Compilare: main.cpp: In function 'bool isInvalid()': main.cpp:23:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 23 | for (int i = 0; i < s.size(); i++) | ~~^~~~~~~~~~ main.cpp:37:14: warning: unused variable 'dbg' [-Wunused-variable] 37 | bool dbg = isCif(s[i-1]); | ^~~ main.cpp: In function 'int calcul()': main.cpp:52:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 52 | while (it < s.size() && s[it] != ')') | ~~~^~~~~~~~~~