Compilare: main.cpp: In function 'std::vector<int> sub(int&)': main.cpp:15:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 15 | while (i < s.length() && s[i] != ')') | ~~^~~~~~~~~~~~ main.cpp:13:22: warning: unused variable 'c' [-Wunused-variable] 13 | char last = '*', c; | ^ main.cpp: In function 'int main()': main.cpp:57:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 57 | for (int i = 0; i < v.size(); i++) | ~~^~~~~~~~~~