Compilare: user.cpp: In function 'void init(char)': user.cpp:9: warning: array subscript has type 'char' user.cpp: In function 'char succesor(char)': user.cpp:14: warning: array subscript has type 'char' user.cpp:16: warning: array subscript has type 'char' user.cpp: In function 'char valid(char)': user.cpp:26: warning: array subscript has type 'char' user.cpp:26: warning: array subscript has type 'char' user.cpp: In function 'void tiparire()': user.cpp:43: warning: array subscript has type 'char'