/* Adds a link to the back of the deque
param: q - pointer to the deque
param: val - value for the link to be added
pre: q is not null
post: a link storing val is added to the back of the deque
*/
void addBackCirListDeque( struct cirListDeque *q, TYPE val )
{
assert( q != NULL );
/* Update information about q itself */
q->size += 1;
/* Create a new link with the value */
struct DLink *newLnk = _createLink( val );
/* Update pointers of new link */
_addLinkAfter( q, q->Sentinel->prev, newLnk );
}
/* Adds a link after another link
param: q pointer to the deque
param: lnk pointer to the existing link in the deque
param: v value of the new link to be added after the existing link
pre: q is not null
pre: lnk is not null
pre: lnk is in the deque
post: the new link is added into the deque after the existing link
*/
void _addLinkAfter(struct cirListDeque *q, struct DLink *lnk, TYPE v)
{
/* DONE: you must write this */
assert(q != 0 && lnk != 0);
struct DLink *newLink = _createLink(v);
lnk->next->prev = newLink;
newLink->next = lnk->next;
lnk->next = newLink;
newLink->prev = lnk;
q->size++;
}
/* Adds a link after another link
param: q pointer to the deque
param: lnk pointer to the existing link in the deque
param: v value of the new link to be added after the existing link
pre: q is not null
pre: lnk is not null
pre: lnk is in the deque
post: the new link is added into the deque after the existing link
*/
void _addLinkAfter(struct cirListDeque *q, struct DLink *lnk, TYPE v){
struct DLink *newLink = _createLink(v);
assert(q);
assert(lnk);
newLink->prev = lnk;
newLink->next = lnk->next;
lnk->next->prev = newLink;
lnk->next = newLink;
q->size++;
}
/* Adds a link to the front of the deque
param: q pointer to the deque
param: val value for the link to be added
pre: q is not null
post: a link storing val is added to the front of the deque
*/
void addFrontCirListDeque(struct cirListDeque *q, TYPE val)
{
struct DLink * lnk = _createLink(val);
if (isEmptyCirListDeque(q))
{
/* if q is currently empty, the added link becomes the only link in the deque */
lnk->next = lnk;
lnk->prev = lnk;
q->size++;
/* change last to the newly added link */
q->last = lnk;
}
else
_addLinkAfter(q, q->last, lnk);
}
/* Adds a link after another link
param: q pointer to the deque
param: lnk pointer to the existing link in the deque
param: v value of the new link to be added after the existing link
pre: q is not null
pre: lnk is not null
pre: lnk is in the deque
post: the new link is added into the deque after the existing link
*/
void _addLinkAfter(struct cirListDeque *q, struct DLink *lnk, TYPE v)
{
/* FIXME: you must write this */
/* check null */
assert(q != NULL);
assert(lnk != NULL);
assert(lnk->next != 0);
assert(lnk->prev != 0);
/* create the link and update pointers */
struct DLink *newLink = _createLink(v);
lnk->next->prev = newLink;
newLink->next = lnk->next;
lnk->next = newLink;
newLink->prev = lnk;
q->size++;
}
/* Adds a link after another link
param: q pointer to the deque
param: lnk pointer to the existing link in the deque
param: v value of the new link to be added after the existing link
pre: q is not null
pre: lnk is not null
pre: lnk is in the deque
post: the new link is added into the deque after the existing link
*/
void _addLinkAfter(struct cirListDeque *q, struct DLink *lnk, TYPE v)
{
/* FIXME: you must write this */
assert (q != 0); /* q is not null */
assert (lnk != 0); /* lnk is not null */
/* lnk is in the deque */
assert (lnk->next != 0);
assert (lnk->prev != 0);
/*assign a pointer to iterate through list*/
struct DLink *newLink = _createLink(v);
newLink->next = lnk->next; /* pass lnk's next to the newLink */
newLink->prev = lnk;
lnk->next->prev = newLink;
lnk->next = newLink;
q->size++;
}
