Compilare: main.cpp: In function 'int isBalanced(std::string)': main.cpp:18:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 18 | for(int i = 0; i < s.length(); i++) | ~~^~~~~~~~~~~~ main.cpp:57:21: warning: ignoring return value of 'bool std::stack<_Tp, _Sequence>::empty() const [with _Tp = char; _Sequence = std::deque<char, std::allocator<char> >]', declared with attribute 'nodiscard' [-Wunused-result] 57 | st.empty(); | ~~~~~~~~^~ In file included from /usr/include/c++/12.2.1/stack:61, from main.cpp:2: /usr/include/c++/12.2.1/bits/stl_stack.h:217:7: note: declared here 217 | empty() const | ^~~~~