Compilare: user.cpp: In member function ‘bool Sir::operator<(const Sir&) const’: user.cpp:19:26: warning: array subscript has type ‘char’ [-Wchar-subscripts] if ( val[x[i]] < val[a.x[i]] ) ^ user.cpp:19:40: warning: array subscript has type ‘char’ [-Wchar-subscripts] if ( val[x[i]] < val[a.x[i]] ) ^ user.cpp:22:30: warning: array subscript has type ‘char’ [-Wchar-subscripts] if ( val[x[i]] > val[a.x[i]] ) ^ user.cpp:22:44: warning: array subscript has type ‘char’ [-Wchar-subscripts] if ( val[x[i]] > val[a.x[i]] ) ^ user.cpp: In function ‘void Read()’: user.cpp:49:17: warning: array subscript has type ‘char’ [-Wchar-subscripts] val[x[i]] = i; ^