Compilare: main.cpp: In function 'void prec_()': main.cpp:109:9: warning: array subscript has type 'char' [-Wchar-subscripts] ok[a] = ok[a ^ 0x20] = 1; ^ main.cpp:111:9: warning: array subscript has type 'char' [-Wchar-subscripts] ok[a] = 1; ^ main.cpp: In function 'void input()': main.cpp:119:17: warning: array subscript has type 'char' [-Wchar-subscripts] for (; ok[*cur]; ++cur); ^ main.cpp:121:18: warning: array subscript has type 'char' [-Wchar-subscripts] for (; !ok[*cur]; ++cur); ^