Compilare: user.cpp: In function ‘int main()’: user.cpp:23:16: warning: array subscript has type ‘char’ [-Wchar-subscripts] ap[s[i]]++; ^ user.cpp:26:25: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (inq[s[i]]) continue; ^ user.cpp:27:59: warning: array subscript has type ‘char’ [-Wchar-subscripts] while (st.size() && s[i] < st.top() && ap[st.top()]>1) ap[st.top()]--, inq[st.top()]=0, st.pop(); ^ user.cpp:27:75: warning: array subscript has type ‘char’ [-Wchar-subscripts] while (st.size() && s[i] < st.top() && ap[st.top()]>1) ap[st.top()]--, inq[st.top()]=0, st.pop(); ^ user.cpp:27:92: warning: array subscript has type ‘char’ [-Wchar-subscripts] while (st.size() && s[i] < st.top() && ap[st.top()]>1) ap[st.top()]--, inq[st.top()]=0, st.pop(); ^ user.cpp:28:17: warning: array subscript has type ‘char’ [-Wchar-subscripts] inq[s[i]]=1; st.push(s[i]); ^