Compilare: main.cpp: In function 'int main()': main.cpp:20:16: warning: array subscript has type 'char' [-Wchar-subscripts] fr[s[i]]++; ^ main.cpp:24:31: warning: array subscript has type 'char' [-Wchar-subscripts] if(!aparitiestiva[s[i]]) ^ main.cpp:26:61: warning: array subscript has type 'char' [-Wchar-subscripts] while(!S.empty() and s[i]<S.top() and fr[S.top()]) ^ main.cpp:28:38: warning: array subscript has type 'char' [-Wchar-subscripts] aparitiestiva[S.top()]=0; ^ main.cpp:32:31: warning: array subscript has type 'char' [-Wchar-subscripts] aparitiestiva[s[i]]=1; ^ main.cpp:34:16: warning: array subscript has type 'char' [-Wchar-subscripts] fr[s[i]]--; ^