/// <summary>
/// Coada FIFO de dimensiune fixa
/// </summary>
/// <typeparam name="Item"></typeparam>
class Queue1<Item> : IEnumerable<Item>
{
private Item[] data;
private int capacity=14 ;
private int left = 0, right = 0;
/// <summary>
/// Crearea unei cozi fara nici un element
/// </summary>
public Queue1()
{
data = new Item[capacity];
}
public Queue1(int capacity)
{
this.capacity = capacity;
data = new Item[capacity];
}
int nextPoz(int index)
{
if (index < capacity - 1)
return index + 1;
else
return 0;
}
/// <summary>
/// Adaugarea unui element in coada
/// </summary>
/// <param name="item">Elementul ce se adauga</param>
public void enqueue(Item item)
{
/*
data[right] = item;
if (right == capacity - 1)
{
right = 0;
}
else
{
right += 1;
}
*/
if (left == nextPoz(right))
throw new QueueFullException();
else
data[right] = item;
right = nextPoz(right);
}
/// <summary>
/// Eliminarea elementului care a fost adaugat cel mai demult
/// </summary>
/// <returns></returns>
public Item dequeue()
{
/*
Item x = data[left];
if (left == capacity - 1)
left = 0;
else
left += 1;
return x;
*/
Item x;
if (left == right)
throw new QueueEmptyException();
else
x = data[left];
left = nextPoz(left);
return x;
}
/// <summary>
/// Este goala coada?
/// </summary>
/// <returns></returns>
public bool isEmpty()
{
return left == right;
}
/// <summary>
/// Numarul de elemente din coada
/// </summary>
/// <returns></returns>
public int size()
{
if (left < right)
return right - left;
else
return left - right;
}
public IEnumerator<Item> GetEnumerator()
{
if (left < right)
{
for (int i = left; i < right; i++)
{
yield return data[i];
}
}
else
{
for (int j = 0; j < right; j++)
yield return data[j];
for (int i = left; i < capacity; i++)
yield return data[i];
}
}
System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
{
return GetEnumerator();
}
}
class QueueEmptyException : System.Exception
{
}
class QueueFullException : System.Exception
{
}
