Compilare: user.cpp: In function ‘int main()’: user.cpp:11:8: warning: array subscript has type ‘char’ [-Wchar-subscripts] fr[a[1]]++; ^ user.cpp:19:22: warning: array subscript has type ‘char’ [-Wchar-subscripts] fr[a[ultim]]++; ^ user.cpp:20:27: warning: array subscript has type ‘char’ [-Wchar-subscripts] if ( fr[a[ultim]] == 1 ) k++; ^ user.cpp:24:24: warning: array subscript has type ‘char’ [-Wchar-subscripts] while (k>c) {fr[a[prim]]--; ^ user.cpp:25:28: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (fr[a[prim]] == 0 ) k--; ^