Compilare: user.cpp:31:55: warning: multi-character character constant [-Wmultichar] if ( expr[ point ] == 'N' && expr[ point + 1 ] == 'O ' ) ^ user.cpp: In function ‘int eval_not()’: user.cpp:55:33: warning: array subscript has type ‘char’ [-Wchar-subscripts] return val[ expr[ point++ ] ]; ^ user.cpp: In function ‘int main()’: user.cpp:99:16: warning: array subscript has type ‘char’ [-Wchar-subscripts] val[ c ] ^= 1; ^ /tmp/cc9BAqsA.o: In function `main': user.cpp:(.text.startup+0x53): warning: the `gets' function is dangerous and should not be used.