Compilare: main.cpp: In function 'int main()': main.cpp:21:23: warning: array subscript has type 'char' [-Wchar-subscripts] if (query(s)) cnt[i] += 1; ^ main.cpp:27:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j <= ans.size(); ++j) { ~~^~~~~~~~~~~~~ main.cpp:29:16: warning: array subscript has type 'char' [-Wchar-subscripts] while (cnt[i] > 0) { ^ main.cpp:33:10: warning: array subscript has type 'char' [-Wchar-subscripts] cnt[i] -= 1; ^