Compilare: user.cpp: In function ‘int main()’: user.cpp:16:34: warning: array subscript has type ‘char’ [-Wchar-subscripts] ff[x - 'A'][y - 'A'][c] = 1; ^ user.cpp:19:25: warning: array subscript has type ‘char’ [-Wchar-subscripts] f[x - 'a'][c] = 1;; ^ user.cpp:31:17: warning: suggest parentheses around ‘+’ inside ‘>>’ [-Wparentheses] fin>> s + 1; ^