السلام عليكم ....
ممكن احد يساعدني في ذا الكود مو طالع عندي غلط بس مايطلع معي الرن :mellow:
وفيه ميثودين مو راضيه تزبط معي كل مااسويها يكون عندي غلط يالليت اللي فاهملها يعلمني كيف
class Link
{
public long dData; // data item
public Link next; // next link in list
public Link previous; // previous link in list
// -------------------------------------------------------------
public Link(long d) // constructor
{ dData = d; }
// -------------------------------------------------------------
public void displayLink() // display this link
{ System.out.print(dData + " "); }
// -------------------------------------------------------------
} // end class Link
class DoublyLinkedList
{
private Link first; // ref to first item
private Link last; // ref to last item
// -------------------------------------------------------------
public DoublyLinkedList() // constructor
{
first = null; // no items on list yet
last = null;
}
// -------------------------------------------------------------
public boolean isEmpty() // true if no links
{ return first==null; }
// -------------------------------------------------------------
// TO DO:
public void insertFirst(long dd) // insert at front of list
{
Link newLink = new Link(dd); // make new link
if( isEmpty() ) // if empty list,
last = newLink; // newLink <-- last
else
first.previous = newLink; // newLink <-- old first
newLink.next = first; // newLink --> old first
first = newLink; // first --> newLink
}
// -------------------------------------------------------------
// TO DO:
public void insertLast(long dd) // insert at end of list
{
Link newLink = new Link(dd); // make new link
if( isEmpty() ) // if empty list,
first = newLink; // first --> newLink
else
{
last.next = newLink; // old last --> newLink
newLink.previous = last; // old last <-- newLink
}
last = newLink; // newLink <-- last
}
// -------------------------------------------------------------
// TO DO:
public Link deleteFirst() // delete first link
{ // (assumes non-empty list)
Link temp = first;
if(first.next == null) // if only one item
last = null; // null <-- last
else
first.next.previous = null; // null <-- old next
first = first.next; // first --> old next
return temp;
}
// -------------------------------------------------------------
// TO DO:
public Link deleteLast() // delete last link
{ // (assumes non-empty list)
Link temp = last;
if(first.next == null) // if only one item
first = null; // first --> null
else
last.previous.next = null; // old previous --> null
last = last.previous; // old previous <-- last
return temp;
}
// -------------------------------------------------------------
// insert dd just after key
// TO DO:
public boolean insertAfter(long key, long dd)
{ // (assumes non-empty list)
Link current = first; // start at beginning
while(current.dData != key) // until match is found,
{
current = current.next; // move to next link
if(current == null)
return false; // didn't find it
}
Link newLink = new Link(dd); // make new link
if(current==last) // if last link,
{
newLink.next = null; // newLink --> null
last = newLink; // newLink <-- last
}
else // not last link,
{
newLink.next = current.next; // newLink --> old next
// newLink <-- old next
current.next.previous = newLink;
}
newLink.previous = current; // old current <-- newLink
current.next = newLink; // old current --> newLink
return true; // found it, did insertion
}
// -------------------------------------------------------------
// TO DO:
public Link deleteKey(long
key) // delete item w/ given key
{ // (assumes non-empty list)
Link current = first; // start at beginning
while(current.dData != key) // until match is found,
{
current = current.next; // move to next link
if(current == null)
return null; // didn't find it
}
if(current==first) // found it; first item?
first = current.next; // first --> old next
else // not first
// old previous --> old next
current.previous.next = current.next;
if(current==last) // last item?
last = current.previous; // old previous <-- last
else // not last
// old previous <-- old next
current.next.previous = current.previous;
return current; // return value
}
// -------------------------------------------------------------
public void displayForward()
{
System.out.print("List (first-->last): ");
Link current = first; // start at beginning
while(current != null) // until end of list,
{
current.displayLink(); // display data
current = current.next; // move to next link
}
System.out.println("");
}
// -------------------------------------------------------------
// TO DO:
public void displayBackward()
{
System.out.print("List (last-->first): ");
Link current = last; // start at end
while(current != null) // until start of list,
{
current.displayLink(); // display data
current = current.previous; // move to previous link
}
System.out.println("");
}
// -------------------------------------------------------------
// TO DO:
// public Link findFirst(int key) // find first link with given key
// {
// // key must be 1
// if(key == 1)
// first.displayLink();
//
// else
// return null;
// }
//
//
//
//// -------------------------------------------------------------
//// TO DO:
//
// public Link findLast(int key) // find last link with given key
// {
//
//
// }
// -------------------------------------------------------------
} // end class DoublyLinkedList
class DoublyLinkedApp
{
public static void main(String[] args)
{ // make a new list
DoublyLinkedList theList = new DoublyLinkedList();
theList.insertFirst(22); // insert at front
theList.insertFirst(44);
theList.insertFirst(66);
theList.insertLast(11); // insert at rear
theList.insertLast(33);
theList.insertLast(55);
theList.displayForward(); // display list forward
theList.displayBackward(); // display list backward
theList.deleteFirst(); // delete first item
theList.deleteLast(); // delete last item
theList.deleteKey(11); // delete item with key 11
theList.displayForward(); // display list forward
theList.insertAfter(22, 77); // insert 77 after 22
theList.insertAfter(33, 88); // insert 88 after 33
theList.displayForward(); // display list forward
// find first link with given key
// TO DO:
//theList.findFirst(1);
// find last link with given key
// TO DO:
} // end main()
} // end class DoublyLinkedAppذولا الميثودين .....
// -------------------------------------------------------------
// TO DO:
// public Link findFirst(int key) // find first link with given key
// {
// // key must be 1
// if(key == 1)
// first.displayLink();
//
// else
// return null;
// }
//
//
//
//// -------------------------------------------------------------
//// TO DO:
//
// public Link findLast(int key) // find last link with given key
// {
//
//
// }
// -------------------------------------------------------------
} // end class DoublyLinkedList