Unit 3 Chapter 5 Linked Lists Code Flashcards
1
Q
sorted list
A
////////////////////////////////////////////////////////////////
class Link
{
public long dData; // data item
public Link next; // next link in list
// -------------------------------------------------------------
public Link(long dd) // constructor
{ dData = dd; }
// -------------------------------------------------------------
public void displayLink() // display this link
{ System.out.print(dData + " "); }
} // end class Link
////////////////////////////////////////////////////////////////
class SortedList
{
private Link first; // ref to first item
// -------------------------------------------------------------
public SortedList() // constructor
{ first = null; }
// -------------------------------------------------------------
public boolean isEmpty() // true if no links
{ return (first==null); }
// -------------------------------------------------------------
public void insert(long key) // insert, in order
{
Link newLink = new Link(key); // make new link
Link previous = null; // start at first
Link current = first;
// until end of list,
while(current != null && key > current.dData)
{ // or key > current,
previous = current;
current = current.next; // go to next item
}
if(previous==null) // at beginning of list
first = newLink; // first --> newLink
else // not at beginning
previous.next = newLink; // old prev --> newLink
newLink.next = current; // newLink --> old currnt
} // end insert()
// -------------------------------------------------------------
public Link remove() // return & delete first link
{ // (assumes non-empty list)
Link temp = first; // save first
first = first.next; // delete first
return temp; // return value
}
// -------------------------------------------------------------
public void displayList()
{
System.out.print("List (first-->last): ");
Link current = first; // start at beginning of list
while(current != null) // until end of list,
{
current.displayLink(); // print data
current = current.next; // move to next link
}
System.out.println("");
}
} // end class SortedList
////////////////////////////////////////////////////////////////
class SortedListApp
{
public static void main(String[] args)
{ // create new list
SortedList theSortedList = new SortedList();
theSortedList.insert(20); // insert 2 items
theSortedList.insert(40);
theSortedList.displayList(); // display list theSortedList.insert(10); // insert 3 more items theSortedList.insert(30); theSortedList.insert(50); theSortedList.displayList(); // display list theSortedList.remove(); // remove an item
theSortedList.displayList(); // display list
} // end main()
} // end class SortedListApp
////////////////////////////////////////////////////////////////
2
Q
insertion sort
A
////////////////////////////////////////////////////////////////
class Link
{
public long dData; // data item
public Link next; // next link in list
// -------------------------------------------------------------
public Link(long dd) // constructor
{ dData = dd; }
// -------------------------------------------------------------
} // end class Link
////////////////////////////////////////////////////////////////
class SortedList
{
private Link first; // ref to first item on list
// -------------------------------------------------------------
public SortedList() // constructor (no args)
{ first = null; } // initialize list
// -------------------------------------------------------------
public SortedList(Link[] linkArr) // constructor (array
{ // as argument)
first = null; // initialize list
for(int j=0; j current.dData)
{ // or key > current,
previous = current;
current = current.next; // go to next item
}
if(previous==null) // at beginning of list
first = k; // first --> k
else // not at beginning
previous.next = k; // old prev --> k
k.next = current; // k --> old currnt
} // end insert()
// -------------------------------------------------------------
public Link remove() // return & delete first link
{ // (assumes non-empty list)
Link temp = first; // save first
first = first.next; // delete first
return temp; // return value
}
// -------------------------------------------------------------
} // end class SortedList
////////////////////////////////////////////////////////////////
class ListInsertionSortApp
{
public static void main(String[] args)
{
int size = 10;
// create array of links
Link[] linkArray = new Link[size];
for(int j=0; j);
} // end main()
} // end class ListInsertionSortApp
////////////////////////////////////////////////////////////////
3
Q
linkStack
A
////////////////////////////////////////////////////////////////
class Link
{
public long dData; // data item
public Link next; // next link in list
// -------------------------------------------------------------
public Link(long dd) // constructor
{ dData = dd; }
// -------------------------------------------------------------
public void displayLink() // display ourself
{ System.out.print(dData + " "); }
} // end class Link
////////////////////////////////////////////////////////////////
class LinkList
{
private Link first; // ref to first item on list
// -------------------------------------------------------------
public LinkList() // constructor
{ first = null; } // no items on list yet
// -------------------------------------------------------------
public boolean isEmpty() // true if list is empty
{ return (first==null); }
// -------------------------------------------------------------
public void insertFirst(long dd) // insert at start of list
{ // make new link
Link newLink = new Link(dd);
newLink.next = first; // newLink --> old first
first = newLink; // first --> newLink
}
// -------------------------------------------------------------
public long deleteFirst() // delete first item
{ // (assumes list not empty)
Link temp = first; // save reference to link
first = first.next; // delete it: first-->old next
return temp.dData; // return deleted link
}
// -------------------------------------------------------------
public void displayList()
{
Link current = first; // start at beginning of list
while(current != null) // until end of list,
{
current.displayLink(); // print data
current = current.next; // move to next link
}
System.out.println("");
}
// -------------------------------------------------------------
} // end class LinkList
////////////////////////////////////////////////////////////////
class LinkStack
{
private LinkList theList;
//--------------------------------------------------------------
public LinkStack() // constructor
{
theList = new LinkList();
}
//--------------------------------------------------------------
public void push(long j) // put item on top of stack
{
theList.insertFirst(j);
}
//--------------------------------------------------------------
public long pop() // take item from top of stack
{
return theList.deleteFirst();
}
//--------------------------------------------------------------
public boolean isEmpty() // true if stack is empty
{
return ( theList.isEmpty() );
}
//--------------------------------------------------------------
public void displayStack()
{
System.out.print("Stack (top-->bottom): ");
theList.displayList();
}
//--------------------------------------------------------------
} // end class LinkStack
////////////////////////////////////////////////////////////////
class LinkStackApp
{
public static void main(String[] args)
{
LinkStack theStack = new LinkStack(); // make stack
theStack.push(20); // push items theStack.push(40); theStack.displayStack(); // display stack theStack.push(60); // push items theStack.push(80); theStack.displayStack(); // display stack theStack.pop(); // pop items theStack.pop();
theStack.displayStack(); // display stack
} // end main()
} // end class LinkStackApp
////////////////////////////////////////////////////////////////
4
Q
link queue
A
////////////////////////////////////////////////////////////////
class Link
{
public long dData; // data item
public Link next; // next link in list
// -------------------------------------------------------------
public Link(long d) // constructor
{ dData = d; }
// -------------------------------------------------------------
public void displayLink() // display this link
{ System.out.print(dData + " "); }
// -------------------------------------------------------------
} // end class Link
////////////////////////////////////////////////////////////////
class FirstLastList
{
private Link first; // ref to first item
private Link last; // ref to last item
// -------------------------------------------------------------
public FirstLastList() // constructor
{
first = null; // no items on list yet
last = null;
}
// -------------------------------------------------------------
public boolean isEmpty() // true if no links
{ return first==null; }
// -------------------------------------------------------------
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
last = newLink; // newLink old next
return temp;
}
// -------------------------------------------------------------
public void displayList()
{
Link current = first; // start at beginning
while(current != null) // until end of list,
{
current.displayLink(); // print data
current = current.next; // move to next link
}
System.out.println("");
}
// -------------------------------------------------------------
} // end class FirstLastList
////////////////////////////////////////////////////////////////
class LinkQueue
{
private FirstLastList theList;
//--------------------------------------------------------------
public LinkQueue() // constructor
{ theList = new FirstLastList(); } // make a 2-ended list
//--------------------------------------------------------------
public boolean isEmpty() // true if queue is empty
{ return theList.isEmpty(); }
//--------------------------------------------------------------
public void insert(long j) // insert, rear of queue
{ theList.insertLast(j); }
//--------------------------------------------------------------
public long remove() // remove, front of queue
{ return theList.deleteFirst(); }
//--------------------------------------------------------------
public void displayQueue()
{
System.out.print("Queue (front-->rear): ");
theList.displayList();
}
//--------------------------------------------------------------
} // end class LinkQueue
////////////////////////////////////////////////////////////////
class LinkQueueApp
{
public static void main(String[] args)
{
LinkQueue theQueue = new LinkQueue();
theQueue.insert(20); // insert items
theQueue.insert(40);
theQueue.displayQueue(); // display queue theQueue.insert(60); // insert items theQueue.insert(80); theQueue.displayQueue(); // display queue theQueue.remove(); // remove items theQueue.remove();
theQueue.displayQueue(); // display queue
} // end main()
} // end class LinkQueueApp
////////////////////////////////////////////////////////////////
5
Q
linkList2 adds methods to search a linked list and delete an item.
A
// -------------------------------------------------------------
public Link find(int key) // find link with given key
{ // (assumes non-empty list)
Link current = first; // start at 'first'
while(current.iData != key) // while no match,
{
if(current.next == null) // if end of list,
return null; // didn't find it
else // not end of list,
current = current.next; // go to next link
}
return current; // found it
}
// -------------------------------------------------------------
public Link delete(int key) // delete link with given key
{ // (assumes non-empty list)
Link current = first; // search for link
Link previous = first;
while(current.iData != key)
{
if(current.next == null)
return null; // didn't find it
else
{
previous = current; // go to next link
current = current.next;
}
} // found it
if(current == first) // if first link,
first = first.next; // change first
else // otherwise,
previous.next = current.next; // bypass it
return current;
}
// -------------------------------------------------------------
6
Q
linkList
A
////////////////////////////////////////////////////////////////
class Link
{
public int iData; // data item
public double dData; // data item
public Link next; // next link in list
// -------------------------------------------------------------
public Link(int id, double dd) // constructor
{
iData = id; // initialize data
dData = dd; // ('next' is automatically
} // set to null)
// -------------------------------------------------------------
public void displayLink() // display ourself
{
System.out.print("{" + iData + ", " + dData + "} ");
}
} // end class Link
////////////////////////////////////////////////////////////////
class LinkList
{
private Link first; // ref to first link on list
// -------------------------------------------------------------
public LinkList() // constructor
{
first = null; // no links on list yet
}
// -------------------------------------------------------------
public boolean isEmpty() // true if list is empty
{
return (first==null);
}
// -------------------------------------------------------------
// insert at start of list
public void insertFirst(int id, double dd)
{ // make new link
Link newLink = new Link(id, dd);
newLink.next = first; // newLink --> old first
first = newLink; // first --> newLink
}
// -------------------------------------------------------------
public Link deleteFirst() // delete first item
{ // (assumes list not empty)
Link temp = first; // save reference to link
first = first.next; // delete it: first-->old next
return temp; // return deleted link
}
// -------------------------------------------------------------
public void displayList()
{
System.out.print("List (first-->last): ");
Link current = first; // start at beginning of list
while(current != null) // until end of list,
{
current.displayLink(); // print data
current = current.next; // move to next link
}
System.out.println("");
}
// -------------------------------------------------------------
} // end class LinkList
////////////////////////////////////////////////////////////////
class LinkListApp
{
public static void main(String[] args)
{
LinkList theList = new LinkList(); // make new list
theList.insertFirst(22, 2.99); // insert four items
theList.insertFirst(44, 4.99);
theList.insertFirst(66, 6.99);
theList.insertFirst(88, 8.99);
theList.displayList(); // display list
while( !theList.isEmpty() ) // until it's empty,
{
Link aLink = theList.deleteFirst(); // delete link
System.out.print("Deleted "); // display it
aLink.displayLink();
System.out.println("");
}
theList.displayList(); // display list
} // end main() } // end class LinkListApp ////////////////////////////////////////////////////////////////
7
Q
interIterator
A
import java.io.*; // for I/O
////////////////////////////////////////////////////////////////
class Link
{
public long dData; // data item
public Link next; // next link in list
// -------------------------------------------------------------
public Link(long dd) // constructor
{ dData = dd; }
// -------------------------------------------------------------
public void displayLink() // display ourself
{ System.out.print(dData + " "); }
} // end class Link
////////////////////////////////////////////////////////////////
class LinkList
{
private Link first; // ref to first item on list
// -------------------------------------------------------------
public LinkList() // constructor
{ first = null; } // no items on list yet
// -------------------------------------------------------------
public Link getFirst() // get value of first
{ return first; }
// -------------------------------------------------------------
public void setFirst(Link f) // set first to new link
{ first = f; }
// -------------------------------------------------------------
public boolean isEmpty() // true if list is empty
{ return first==null; }
// -------------------------------------------------------------
public ListIterator getIterator() // return iterator
{
return new ListIterator(this); // initialized with
} // this list
// -------------------------------------------------------------
public void displayList()
{
Link current = first; // start at beginning of list
while(current != null) // until end of list,
{
current.displayLink(); // print data
current = current.next; // move to next link
}
System.out.println("");
}
// -------------------------------------------------------------
} // end class LinkList
////////////////////////////////////////////////////////////////
class ListIterator
{
private Link current; // current link
private Link previous; // previous link
private LinkList ourList; // our linked list
//--------------------------------------------------------------
public ListIterator(LinkList list) // constructor
{
ourList = list;
reset();
}
//--------------------------------------------------------------
public void reset() // start at 'first'
{
current = ourList.getFirst();
previous = null;
}
//--------------------------------------------------------------
public boolean atEnd() // true if last link
{ return (current.next==null); }
//--------------------------------------------------------------
public void nextLink() // go to next link
{
previous = current;
current = current.next;
}
//--------------------------------------------------------------
public Link getCurrent() // get current link
{ return current; }
//--------------------------------------------------------------
public void insertAfter(long dd) // insert after
{ // current link
Link newLink = new Link(dd);
if( ourList.isEmpty() ) // empty list
{
ourList.setFirst(newLink);
current = newLink;
}
else // not empty
{
newLink.next = current.next;
current.next = newLink;
nextLink(); // point to new link
}
}
//--------------------------------------------------------------
public void insertBefore(long dd) // insert before
{ // current link
Link newLink = new Link(dd);
if(previous == null) // beginning of list
{ // (or empty list)
newLink.next = ourList.getFirst();
ourList.setFirst(newLink);
reset();
}
else // not beginning
{
newLink.next = previous.next;
previous.next = newLink;
current = newLink;
}
} //-------------------------------------------------------------- public long deleteCurrent() // delete item at current
{
long value = current.dData;
if(previous == null) // beginning of list
{
ourList.setFirst(current.next);
reset();
}
else // not beginning
{
previous.next = current.next;
if( atEnd() )
reset();
else
current = current.next;
}
return value;
} //-------------------------------------------------------------- } // end class ListIterator //////////////////////////////////////////////////////////////// class InterIterApp { public static void main(String[] args) throws IOException
{
LinkList theList = new LinkList(); // new list
ListIterator iter1 = theList.getIterator(); // new iter
long value;
iter1. insertAfter(20); // insert items
iter1. insertAfter(40);
iter1. insertAfter(80);
iter1. insertBefore(60);
while(true)
{
System.out.print("Enter first letter of show, reset, ");
System.out.print("next, get, before, after, delete: ");
System.out.flush();
int choice = getChar(); // get user's option
switch(choice)
{
case 's': // show list
if( !theList.isEmpty() )
theList.displayList();
else
System.out.println("List is empty");
break;
case 'r': // reset (to first)
iter1.reset();
break;
case 'n': // advance to next item
if( !theList.isEmpty() && !iter1.atEnd() )
iter1.nextLink();
else
System.out.println("Can't go to next link");
break;
case 'g': // get current item
if( !theList.isEmpty() )
{
value = iter1.getCurrent().dData;
System.out.println("Returned " + value);
}
else
System.out.println("List is empty");
break;
case 'b': // insert before current
System.out.print("Enter value to insert: ");
System.out.flush();
value = getInt();
iter1.insertBefore(value);
break;
case 'a': // insert after current
System.out.print("Enter value to insert: ");
System.out.flush();
value = getInt();
iter1.insertAfter(value);
break;
case 'd': // delete current item
if( !theList.isEmpty() )
{
value = iter1.deleteCurrent();
System.out.println("Deleted " + value);
}
else
System.out.println("Can't delete");
break;
default:
System.out.println("Invalid entry");
} // end switch
} // end while
} // end main()
//--------------------------------------------------------------
public static String getString() throws IOException
{
InputStreamReader isr = new InputStreamReader(System.in);
BufferedReader br = new BufferedReader(isr);
String s = br.readLine();
return s;
}
//-------------------------------------------------------------
public static char getChar() throws IOException
{
String s = getString();
return s.charAt(0);
}
//-------------------------------------------------------------
public static int getInt() throws IOException
{
String s = getString();
return Integer.parseInt(s);
}
//-------------------------------------------------------------
} // end class InterIterApp
////////////////////////////////////////////////////////////////
8
Q
firstLastLIst
A
////////////////////////////////////////////////////////////////
class Link
{
public long dData; // data item
public Link next; // next link in list
// -------------------------------------------------------------
public Link(long d) // constructor
{ dData = d; }
// -------------------------------------------------------------
public void displayLink() // display this link
{ System.out.print(dData + " "); }
// -------------------------------------------------------------
} // end class Link
////////////////////////////////////////////////////////////////
class FirstLastList
{
private Link first; // ref to first link
private Link last; // ref to last link
// -------------------------------------------------------------
public FirstLastList() // constructor
{
first = null; // no links on list yet
last = null;
}
// -------------------------------------------------------------
public boolean isEmpty() // true if no links
{ return first==null; }
// -------------------------------------------------------------
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 old first
first = newLink; // first --> newLink
}
// -------------------------------------------------------------
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
last = newLink; // newLink old next
return temp;
}
// -------------------------------------------------------------
public void displayList()
{
System.out.print("List (first-->last): ");
Link current = first; // start at beginning
while(current != null) // until end of list,
{
current.displayLink(); // print data
current = current.next; // move to next link
}
System.out.println("");
}
// -------------------------------------------------------------
} // end class FirstLastList
////////////////////////////////////////////////////////////////
class FirstLastApp
{
public static void main(String[] args)
{ // make a new list
FirstLastList theList = new FirstLastList();
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.displayList(); // display the list theList.deleteFirst(); // delete first two items theList.deleteFirst();
theList.displayList(); // display again
} // end main()
} // end class FirstLastApp
////////////////////////////////////////////////////////////////
9
Q
doublyLinked
A
////////////////////////////////////////////////////////////////
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; }
// -------------------------------------------------------------
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 old first
first = newLink; // first --> newLink
}
// -------------------------------------------------------------
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 old next
return temp;
}
// -------------------------------------------------------------
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 old next
else // not first
// old previous --> old next
current.previous.next = current.next;
if(current==last) // last item?
last = current.previous; // old previous );
}
// -------------------------------------------------------------
} // 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
} // end main()
} // end class DoublyLinkedApp
////////////////////////////////////////////////////////////////
