Compilare: main.cpp: In function 'void Solve()': main.cpp:66:34: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 66 | for(int j = 0; j < s1.size(); ++j) | ~~^~~~~~~~~~~ main.cpp:68:34: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 68 | for(int j = 1; j < s.size(); ++j) | ~~^~~~~~~~~~ main.cpp:83:34: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 83 | for(int j = 0; j < s1.size(); ++j) | ~~^~~~~~~~~~~ main.cpp:85:34: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 85 | for(int j = 0; j < s.size(); ++j) | ~~^~~~~~~~~~ main.cpp:92:13: warning: array subscript has type 'char' [-Wchar-subscripts] 92 | ans[++ans[0]] = st.top(), st.pop(); | ^~~~~~~~