Compilare: main.cpp: In function 'void prec_()': main.cpp:112:9: warning: array subscript has type 'char' [-Wchar-subscripts] ok[a] = ok[a ^ 0x20] = 1; ^ main.cpp:114:9: warning: array subscript has type 'char' [-Wchar-subscripts] ok[a] = 1; ^ main.cpp: In function 'void input()': main.cpp:122:17: warning: array subscript has type 'char' [-Wchar-subscripts] for (; ok[*cur]; ++cur); ^ main.cpp:124:18: warning: array subscript has type 'char' [-Wchar-subscripts] for (; !ok[*cur]; ++cur); ^