Compilare: main.cpp: In function 'long long int val(std::string)': main.cpp:24:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 24 | for (; i < s.size(); i++) | ~~^~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:58:15: warning: unused variable 'j' [-Wunused-variable] 58 | int n, i, j, cont, semn; | ^ main.cpp:58:24: warning: unused variable 'semn' [-Wunused-variable] 58 | int n, i, j, cont, semn; | ^~~~