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JAVA: Hi, Im having trouble with the following program. Below, Ive included Transaction.java, Node.java, LinkedQueue.java, and transactions. ***************Transaction.java***************** /** Represents a transaction */ public class
JAVA: Hi, Im having trouble with the following program. Below, Ive included Transaction.java, Node.java, LinkedQueue.java, and transactions.
***************Transaction.java*****************
/** Represents a transaction */
public class Transaction {
private int number; /** number of shares in the transaction */
private int price; /** price per share in the transaction */
private boolean sell; /** type of the transaction (true if "sell",
false if "buy") */
/** Construct a Transaction with specified type, number, and price
* Parameters:
* s - type of transaction (true if it is a sell transaction,
* false otherwise)
* n - number of shares
* p - price per share
* Postcondition: This Transaction has been initialized with the
* specified type (s), number (n), and price (p)
*/
public Transaction(boolean s, int n, int p) {
sell = s;
number = n;
price = p;
}
/** Determines whether this Transaction is a sell transaction
* or not
* Returns:
* the type of this transaction (true if "sell", false if "buy")
*/
public boolean isSell() {
return sell;
}
/** Get the number of shares of this Transaction
* Returns: the number of shares
*/
public int getNumber() {
return number;
}
/** Get the price per share of this Transaction
* Returns: the price per share
*/
public int getPrice() {
return price;
}
/** Change the number of shares in this Transaction
* Parameter: newNumber - the new number of shares
* Postcondition:
* This Transaction's number of shares has been changed
* to the new number of shares (newNumber)
*/
public void changeNumber(int newNumber) {
number = newNumber;
}
/** Returns a string representation of the transaction */
public String toString(){
if (sell)
return ("Sell " + number + " at $" + price);
else
return ("Buy " + number + " at $" + price);
}
}
************* Node.java ******************
// File: Node.java from the package edu.colorado.nodes
// Complete documentation is available from the Node link in:
// http://www.cs.colorado.edu/~main/docs
// package edu.colorado.nodes;
/******************************************************************************
* A Node provides a generic node for a linked list. Each node
* contains a piece of data (which is a reference to an E object) and a link
* (which is a reference to the next node of the list). The reference stored
* in a node can be null.
*
* @note
* Lists of nodes can be made of any length, limited only by the amount of
* free memory in the heap. But beyond Integer.MAX_VALUE (2,147,483,647),
* the answer from listLength is incorrect because of arithmetic
* overflow.
* @see
*
* Java Source Code for this class
* (www.cs.colorado.edu/~main/edu/coloradoodes/Node.java)
*
* @author Michael Main
* (main@colorado.edu)
*
* @version
* Jul 17, 2005
*
* @see BooleanNode
* @see ByteNode
* @see CharNode
* @see DoubleNode
* @see FloatNode
* @see IntNode
* @see LongNode
* @see ShortNode
******************************************************************************/
public class Node
{
// Invariant of the Node class:
// 1. Each node has one reference to an E Object, stored in the instance
// variable data.
// 2. For the final node of a list, the link part is null.
// Otherwise, the link part is a reference to the
// next node of the list.
private E data;
private Node link;
/**
* Initialize a node with a specified initial data and link to the next
* node. Note that the initialLink may be the null reference,
* which indicates that the new node has nothing after it.
* @param initialData
* the initial data of this new node
* @param initialLink
* a reference to the node after this new node--this reference may be null
* to indicate that there is no node after this new node.
* @postcondition
* This node contains the specified data and link to the next node.
**/
public Node(E initialData, Node initialLink)
{
data = initialData;
link = initialLink;
}
/**
* Modification method to add a new node after this node.
* @param element
* the data to place in the new node
* @postcondition
* A new node has been created and placed after this node.
* The data for the new node is element. Any other nodes
* that used to be after this node are now after the new node.
* @exception OutOfMemoryError
* Indicates that there is insufficient memory for a new
* Node.
**/
public void addNodeAfter(E element)
{
link = new Node(element, link);
}
/**
* Accessor method to get the data from this node.
* @param - none
* @return
* the data from this node
**/
public E getData( )
{
return data;
}
/**
* Accessor method to get a reference to the next node after this node.
* @param - none
* @return
* a reference to the node after this node (or the null reference if there
* is nothing after this node)
**/
public Node getLink( )
{
return link;
}
/**
* Copy a list.
* @param source
* the head of a linked list that will be copied (which may be
* an empty list in where source is null)
* @return
* The method has made a copy of the linked list starting at
* source. The return value is the head reference for the
* copy.
* @exception OutOfMemoryError
* Indicates that there is insufficient memory for the new list.
**/
public static Node listCopy(Node source)
{
Node copyHead;
Node copyTail;
// Handle the special case of the empty list.
if (source == null)
return null;
// Make the first node for the newly created list.
copyHead = new Node(source.data, null);
copyTail = copyHead;
// Make the rest of the nodes for the newly created list.
while (source.link != null)
{
source = source.link;
copyTail.addNodeAfter(source.data);
copyTail = copyTail.link;
}
// Return the head reference for the new list.
return copyHead;
}
/**
* Copy a list, returning both a head and tail reference for the copy.
* @param source
* the head of a linked list that will be copied (which may be
* an empty list in where source is null)
* @return
* The method has made a copy of the linked list starting at
* source. The return value is an
* array where the [0] element is a head reference for the copy and the [1]
* element is a tail reference for the copy.
* @exception OutOfMemoryError
* Indicates that there is insufficient memory for the new list.
**/
public static Node[ ] listCopyWithTail(Node source)
{
Node copyHead;
Node copyTail;
Node[ ] answer = (Node[]) new Object[2];
// Handle the special case of the empty list.
if (source == null)
return answer; // The answer has two null references .
// Make the first node for the newly created list.
copyHead = new Node(source.data, null);
copyTail = copyHead;
// Make the rest of the nodes for the newly created list.
while (source.link != null)
{
source = source.link;
copyTail.addNodeAfter(source.data);
copyTail = copyTail.link;
}
// Return the head and tail references.
answer[0] = copyHead;
answer[1] = copyTail;
return answer;
}
/**
* Compute the number of nodes in a linked list.
* @param head
* the head reference for a linked list (which may be an empty list
* with a null head)
* @return
* the number of nodes in the list with the given head
* @note
* A wrong answer occurs for lists longer than Int.MAX_VALUE.
**/
public static int listLength(Node head)
{
Node cursor;
int answer;
answer = 0;
for (cursor = head; cursor != null; cursor = cursor.link)
answer++;
return answer;
}
/**
* Copy part of a list, providing a head and tail reference for the new copy.
* @param start/end
* references to two nodes of a linked list
* @param copyHead/copyTail
* the method sets these to refer to the head and tail node of the new
* list that is created
* @precondition
* start and end are non-null references to nodes
* on the same linked list,
* with the start node at or before the end node.
* @return
* The method has made a copy of the part of a linked list, from the
* specified start node to the specified end node. The return value is an
* array where the [0] component is a head reference for the copy and the
* [1] component is a tail reference for the copy.
* @exception IllegalArgumentException
* Indicates that start and end do not satisfy
* the precondition.
* @exception OutOfMemoryError
* Indicates that there is insufficient memory for the new list.
**/
public static Node[ ] listPart(Node start, Node end)
{
Node copyHead;
Node copyTail;
Node cursor;
Node[ ] answer = (Node[]) new Object[2];
// Check for illegal null at start or end.
if (start == null)
throw new IllegalArgumentException("start is null");
if (end == null)
throw new IllegalArgumentException("end is null");
// Make the first node for the newly created list.
copyHead = new Node(start.data, null);
copyTail = copyHead;
cursor = start;
// Make the rest of the nodes for the newly created list.
while (cursor != end)
{
cursor = cursor.link;
if (cursor == null)
throw new IllegalArgumentException
("end node was not found on the list");
copyTail.addNodeAfter(cursor.data);
copyTail = copyTail.link;
}
// Return the head and tail references
answer[0] = copyHead;
answer[1] = copyTail;
return answer;
}
/**
* Find a node at a specified position in a linked list.
* @param head
* the head reference for a linked list (which may be an empty list in
* which case the head is null)
* @param position
* a node number
* @precondition
* position > 0.
* @return
* The return value is a reference to the node at the specified position in
* the list. (The head node is position 1, the next node is position 2, and
* so on.) If there is no such position (because the list is too short),
* then the null reference is returned.
* @exception IllegalArgumentException
* Indicates that position is zero.
**/
public static Node listPosition(Node head, int position)
{
Node cursor;
int i;
if (position == 0)
throw new IllegalArgumentException("position is zero");
cursor = head;
for (i = 1; (i
cursor = cursor.link;
return cursor;
}
/**
* Search for a particular piece of data in a linked list.
* @param head
* the head reference for a linked list (which may be an empty list in
* which case the head is null)
* @param target
* a target to search for
* @return
* The return value is a reference to the first node that contains the
* specified target. If the target is non-null, then the
* target.equals method is used to find such a node.
* The target may also be null, in which case the return value is a
* reference to the first node that contains a null reference for its
* data. If there is no node that contains the target, then the null
* reference is returned.
**/
public static Node listSearch(Node head, E target)
{
Node cursor;
if (target == null)
{ // Search for a node in which the data is the null reference.
for (cursor = head; cursor != null; cursor = cursor.link)
if (cursor.data == null)
return cursor;
}
else
{ // Search for a node that contains the non-null target.
for (cursor = head; cursor != null; cursor = cursor.link)
if (target.equals(cursor.data))
return cursor;
}
return null;
}
/**
* Modification method to remove the node after this node.
* @param - none
* @precondition
* This node must not be the tail node of the list.
* @postcondition
* The node after this node has been removed from the linked list.
* If there were further nodes after that one, they are still
* present on the list.
* @exception NullPointerException
* Indicates that this was the tail node of the list, so there is nothing
* after it to remove.
**/
public void removeNodeAfter( )
{
link = link.link;
}
/**
* Modification method to set the data in this node.
* @param newData
* the new data to place in this node
* @postcondition
* The data of this node has been set to newData.
* This data is allowed to be null.
**/
public void setData(E newData)
{
data = newData;
}
/**
* Modification method to set the link to the next node after this node.
* @param newLink
* a reference to the node that should appear after this node in the linked
* list (or the null reference if there is no node after this node)
* @postcondition
* The link to the node after this node has been set to newLink.
* Any other node (that used to be in this link) is no longer connected to
* this node.
**/
public void setLink(Node newLink)
{
link = newLink;
}
}
************* LinkedQueue.java *******************
// File: LinkedQueue.java from the package edu.colorado.collections
// Complete documentation is available from the LinkedQueue link in:
// http://www.cs.colorado.edu/~main/docs/
//package edu.colorado.collections;
import java.util.NoSuchElementException;
//import edu.colorado.nodes.Node;
/******************************************************************************
* A
LinkedQueue
is a queue of references to E objects. *
*
- Limitations:
* Beyond
Int.MAX_VALUE
items, size
is wrong. *
*
* Java Source Code for this class:
*
* http://www.cs.colorado.edu/~main/edu/colorado/collections/LinkedQueue.java
*
*
* @author Michael Main
* (main@colorado.edu)
*
* @version
* Jul 21, 2005
*
* @see ArrayQueue
******************************************************************************/
public class LinkedQueue implements Cloneable
{
// Invariant of the LinkedQueue class:
// 1. The number of items in the queue is stored in the instance variable
// manyNodes.
// 2. The items in the queue are stored in a linked list, with the front
// of the queue stored at the head node, and the rear of the queue at
// the final node.
// 3. For a non-empty queue, the instance variable front is the head
// reference of the linked list of items and the instance variable rear
// is the tail reference of the linked list. For an empty queue, both
// front and rear are the null reference.
private int manyNodes;
private Node front;
private Node rear;
/**
* Initialize an empty queue.
* @param - none
* Postcondition:
* This queue is empty.
**/
public LinkedQueue( )
{
front = null;
rear = null;
}
/**
* Put a new a new item in this queue.
* @param
item
* the item to be pushed onto this queue
* Postcondition:
* The item has been pushed onto this queue.
* @exception OutOfMemoryError
* Indicates insufficient memory for increasing the queue's capacity.
* Note:
* An attempt to increase the capacity beyond
*
Integer.MAX_VALUE
will cause the queue to fail with an * arithmetic overflow.
**/
public void add(E item)
{
if (isEmpty( ))
{ // Insert first item.
front = new Node(item, null);
rear = front;
}
else
{ // Insert an item that is not the first.
rear.addNodeAfter(item);
rear = rear.getLink( );
}
manyNodes++;
}
/**
* Generate a copy of this queue.
* @param - none
* @return
* The return value is a copy of this queue. Subsequent changes to the
* copy will not affect the original, nor vice versa. Note that the return
* value must be type cast to an
LinkedQueue
before it can be used. * @exception OutOfMemoryError
* Indicates insufficient memory for creating the clone.
**/
@SuppressWarnings("unchecked")
public LinkedQueue clone( )
{ // Clone a LinkedQueue.
LinkedQueue answer;
Node[ ] cloneInfo;
try
{
answer = (LinkedQueue) super.clone( );
}
catch (CloneNotSupportedException e)
{
// This exception should not occur. But if it does, it would probably indicate a
// programming error that made super.clone unavailable. The most comon error
// The most common error would be forgetting the "Implements Cloneable"
// clause at the start of this class.
throw new RuntimeException
("This class does not implement Cloneable");
}
cloneInfo = Node.listCopyWithTail(front);
answer.front = cloneInfo[0];
answer.rear = cloneInfo[1];
return answer;
}
/**
* Determine whether this queue is empty.
* @param - none
* @return
*
true
if this queue is empty; *
false
otherwise. **/
public boolean isEmpty( )
{
return (manyNodes == 0);
}
/**
* Get the front item, removing it from this queue.
* @param - none
* Precondition:
* This queue is not empty.
* Postcondition:
* The return value is the front item of this queue, and the item has
* been removed.
* @exception NoSuchElementException
* Indicates that this queue is empty.
**/
public E remove( )
{
E answer;
if (manyNodes == 0)
// NoSuchElementException is from java.util and its constructor has no argument.
throw new NoSuchElementException("Queue underflow");
answer = front.getData( );
front = front.getLink( );
manyNodes--;
if (manyNodes == 0)
rear = null;
return answer;
}
/**
* Accessor method to determine the number of items in this queue.
* @param - none
* @return
* the number of items in this queue
**/
public int size( )
{
return manyNodes;
}
}
********* transactions *********
buy 100 shares at $20 each
buy 20 shares at $24 each
buy 200 shares at $36 each
sell 150 shares at $30 each
buy 50 shares at $28 each
sell 100 shares at $32 each
******** transactions1 **********
buy 10 shares at $10 each
buy 20 shares at $5 each
sell 50 shares at $8 each
buy 50 shares at $20 each
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