Compilare: main.cpp: In function 'bool query(std::__cxx11::string)': main.cpp:13:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] return res == s.size(); ~~~~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:29:23: warning: array subscript has type 'char' [-Wchar-subscripts] if (query(s)) cnt[i] += 1; ^ main.cpp:35:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j <= ans.size(); ++j) { ~~^~~~~~~~~~~~~ main.cpp:37:16: warning: array subscript has type 'char' [-Wchar-subscripts] while (cnt[i] > 0) { ^ main.cpp:41:10: warning: array subscript has type 'char' [-Wchar-subscripts] cnt[i] -= 1; ^