6-1, Java.util.LinkedList

6-1, Java.util.LinkedList
Package java.util;
public class linkedlist< E>
Extends abstractsequentiallist< e>
Implements list< e>, deque< e>, cloneable, java.io.Serializable
{
transient int size = 0;
Transient node< e>;
Transient node< e> last;
Public LinkedList () {
}
Public LinkedList (COLLECTION&LT;? Extends e> c) {
This ();
AddAll (c);
}
private void Linkfirst (E e) {
Final node< e> f = A;
Final node< e> newNode = new node<> (null, E, F);
i = NewNode;
if (f = null)
last = NewNode;
Else
F. prev = NewNode;
size++;
modcount++;
}
void Linklast (e e) {
Final node< e> L = last;
Final node< e> newNode = new node<> (l, E, NULL);
last = NewNode;
if (L = = null)
i = NewNode;
Else
L. next = NewNode;
size++;
modcount++;
}
void Linkbefore (e E, node< e> succ) {
Final node< e> pred = succ. prev;
Final node< e> newNode = new Node<> (pred, E, SUCC);
Succ. prev = NewNode;
if (pred = null)
i = NewNode;
Else
pred. Next = NewNode;
size++;
modcount++;
}
Private E Unlinkfirst (node< e> f) {
Final E element = f. Item;
Final node< e> next = f. Next;
F. item = NULL;
F. next = null; Help GC
i = next;
if (next = null)
last = null;
Else
Next. prev = null;
size--;
modcount++;
return element;
}
Private E Unlinklast (node< e> l) {
Final E element = L. item;
Final node< e> prev = L. prev;
L. item = NULL;
L. prev = null;
last = prev;
if (prev = null)
i = null;
Else
Prev. next = null;
size--;
modcount++;
return element;
}
E unlink (node< e> x) {
Final E element = x. item;
Final node< e> next = x. Next;
Final node< e> prev = X. Prev;
if (prev = = null) {
i = next;
} else {
Prev. next = next;
X. prev = null;
}
if (next = null) {
last = prev;
} else {
Next. prev = prev;
X. next = null;
}
X. item = NULL;
size--;
modcount++;
return element;
}
Public E GetFirst () {
Final node< e> f = A;
if (f = null)
throw new Nosuchelementexception ();
return F. Item;
}
Public E GetLast () {
Final node< e> L = last;
if (L = = null)
throw new Nosuchelementexception ();
return L. Item;
}
Public E Removefirst () {
Final node< e> f = A;
if (f = null)
throw new Nosuchelementexception ();
Return Unlinkfirst (f);
}
Public E Removelast () {
Final node< e> L = last;
if (L = = null)
throw new Nosuchelementexception ();
Return Unlinklast (L);
}
public void AddFirst (e e) {Linkfirst (e);}
public void AddLast (E e) {
Linklast (e);
}
Public Boolean contains (Object o) {
return IndexOf (O)!=-1;
}
public int size () {
return size;
}
Public boolean Add (E e) {
Linklast (e);
return true;
}
public boolean remove (Object o) {
if (o = = null) {
for (node< e> x = i x!= null; x = x. Next) {
if (x. item = NULL) {
unlink (x);
return true;
}
}
} else {
for (node< e> x = i x!= null; x = x. Next) {
if (o.equals (x. Item)) {
unlink (x);
return true;
}
}
}
return false;
}
public boolean addall (COLLECTION&LT;? Extends e> c) {
Return AddAll (size, c);
}
public boolean addall (int index, COLLECTION&LT;? Extends e> c) {
Checkpositionindex (index);
Object[] A = C.toarray ();
int numnew = A. Length;
if (numnew = 0)
return false;
node< e> pred, succ;
if (index = = size) {
SUCC = null;
Pred = Last;
} else {
SUCC = node (index);
pred = succ. prev;
}

for (Object o:a) {
@SuppressWarnings ("unchecked") E = (e) o;
node< e> newNode = new Node<> (pred, E, NULL);
if (pred = null)
i = NewNode;
Else
pred. Next = NewNode;
pred = NewNode;
}

if (succ = = null) {
last = pred;
} else {
pred. Next = succ;
Succ. prev = pred;
}

Size + = Numnew;
modcount++;
return true;
}
public void Clear () {
for (node< e> x = A; x!= null;) {
node< e> next = x. Next;
X. item = NULL;
X. next = null;
X. prev = null;
&nb