标签：目标 队列 ogr nta 双向链表 fifo 方便 png near
public class CircularArrayQueue<T> implements QueueADT<T>
{
private final static int DEFAULT_CAPACITY = 100;
private int front, rear, count;
private T[] queue;
/**
* Creates an empty queue using the specified capacity.
* @param initialCapacity the initial size of the circular array queue
*/
public CircularArrayQueue (int initialCapacity)
{
front = rear = count = 0;
queue = (T[]) (new Object[initialCapacity]);
}
/**
* Creates an empty queue using the default capacity.
*/
public CircularArrayQueue()
{
this(DEFAULT_CAPACITY);
}
/**
* Adds the specified element to the rear of this queue, expanding
* the capacity of the queue array if necessary.
* @param element the element to add to the rear of the queue
*/
public void enqueue(T element)
{
if (size() == queue.length)
expandCapacity();
queue[rear] = element;
rear = (rear+1) % queue.length;
count++;
}
/**
* Creates a new array to store the contents of this queue with
* twice the capacity of the old one.
*/
private void expandCapacity()
{
T[] larger = (T[]) (new Object[queue.length *2]);
for (int scan = 0; scan < count; scan++)
{
larger[scan] = queue[front];
front = (front + 1) % queue.length;
}
front = 0;
rear = count;
queue = larger;
}
/**
* Removes the element at the front of this queue and returns a
* reference to it.
* @return the element removed from the front of the queue
* @throws EmptyCollectionException if the queue is empty
*/
public T dequeue() throws EmptyCollectionException
{
if (isEmpty())
throw new EmptyCollectionException("queue");
T result = queue[front];
queue[front] = null;
front = (front+1) % queue.length;
count--;
return result;
}
/**
* Returns a reference to the element at the front of this queue.
* The element is not removed from the queue.
* @return the first element in the queue
* @throws EmptyCollectionException if the queue is empty
*/
public T first() throws EmptyCollectionException
{
if (isEmpty()){
throw new EmptyCollectionException("queue");
}
else
return queue[front];
// To be completed as a Programming Project
}
/**
* Returns true if this queue is empty and false otherwise.
* @return true if this queue is empty
*/
public boolean isEmpty()
{
return count==0;
// To be completed as a Programming Project
}
/**
* Returns the number of elements currently in this queue.
* @return the size of the queue
*/
public int size()
{
return count;
// To be completed as a Programming Project
}
/**
* Returns a string representation of this queue.
* @return the string representation of the queue
*/
public String toString()
{
String result = "";
int a =front;
for (int i = 0 ;i< count;i++){
result += queue[a]+" ";
a++;
}
return result;
// To be completed as a Programming Project
}
}public class LinkedQueue<T> implements QueueADT<T>
{
private int count;
private LinearNode<T> head, tail;
/**
* Creates an empty queue.
*/
public LinkedQueue()
{
count = 0;
head = tail = null;
}
/**
* Adds the specified element to the tail of this queue.
* @param element the element to be added to the tail of the queue
*/
public void enqueue(T element)
{
LinearNode<T> node = new LinearNode<T>(element);
if (isEmpty())
head = node;
else
tail.setNext(node);
tail = node;
count++;
}
/**
* Removes the element at the head of this queue and returns a
* reference to it.
* @return the element at the head of this queue
* @throws EmptyCollectionException if the queue is empty
*/
public T dequeue() throws EmptyCollectionException
{
if (isEmpty())
throw new EmptyCollectionException("queue");
T result = head.getElement();
head = head.getNext();
count--;
if (isEmpty())
tail = null;
return result;
}
/**
* Returns a reference to the element at the head of this queue.
* The element is not removed from the queue.
* @return a reference to the first element in this queue
* @throws EmptyCollectionException if the queue is empty
*/
public T first() throws EmptyCollectionException
{
if (isEmpty()){
throw new EmptyCollectionException("queue");
}
else
return head.getElement() ;
// To be completed as a Programming Project
}
/**
* Returns true if this queue is empty and false otherwise.
* @return true if this queue is empty
*/
public boolean isEmpty()
{
return count == 0;
// To be completed as a Programming Project
}
/**
* Returns the number of elements currently in this queue.
* @return the number of elements in the queue
*/
public int size()
{
return count;
// To be completed as a Programming Project
}
/**
* Returns a string representation of this queue.
* @return the string representation of the queue
*/
public String toString()
{
String result = "" ;
while(head!=null){
result+=head.getElement()+" ";
head = head.getNext();
}
return result;
// To be completed as a Programming Project
}
}学号 2018-2019-20172309 《程序设计与数据结构（下）》第三周学习总结
标签：目标 队列 ogr nta 双向链表 fifo 方便 png near
原文地址：https://www.cnblogs.com/dky-wzw/p/9709920.html
