Directory: ll6 In this version nodes in linked lists have a pointer to an array of function pointers. Currently, the array has two functions: one to print a node and one to deallocate a node. More functions can be added. ll.c: Note new syntax to invoke a function from an array of function pointers. The DEL_VF (delete virtual function) is called from LL_Delete and LL_Empty. main12.c: linked list of int main13.c: linked list of double main14.c: linked list of int and double in the same list. main15.c: linked list of string. Check that strings are deallocated. main16.c: linked list of string and show that we can modify the string. Uses #ifndef around debugging messages. To compile without debugging messages: gcc -Wall -c -DNDEBUG main16.c