USING C PROGRAM: Complete the following main() program to create a Doubly circular sorted linked list structure which will have one alphabet character in each node as shown below. At the end, the list will point to the address of the last character 'Z'.
After creating the circular list, display each node in reverse order (Z, Y, ..., B, A) starting at the head node that is shown by the list.
struct node{
struct node *left;
char letter;
struct node *right;
};
typedef struct node *NODEPTR;
Assume that the getnode() function is already written with the following prototype.
NODEPTR getnode(void);
int main(){
NODEPTR p, list, save;
/* character 'A' initially is inserted into the doubly circular linked list as follows */
p = getnode();
p->letter = 'A';
list = p;
p->right = p;
p->left = p;
...
...
...
return 0;
hint: character 'B' can be obtained as 'B' = 'A' + 1
}