A) Insertion Operation
void insertFirst(int key, int data) {
//create a link
struct node
*link = (struct node*) malloc(sizeof(struct node));
link->key =
key;
link->data =
data;
if(isEmpty()) {
last = link;
} else {
//update
first prev link
head->prev
= link;
}
link->next =
head;
head = link;
}
B) Deletion Operation
struct node* deleteFirst() {
struct node
*tempLink = head;
//if only one
link
if(head->next
== NULL) {
last = NULL;
} else {
head->next->prev = NULL;
}
head =
head->next;
return tempLink;
}
C) Insertion at the End of
an Operation
void insertLast(int key, int data) {
struct node
*link = (struct node*) malloc(sizeof(struct node));
link->key =
key;
link->data =
data;
if(isEmpty()) {
//make it the
last link
last = link;
} else {
last->next
= link;
link->prev
= last;
}
last = link;
}
