Data.Structures.For.Game.Programmers.PART2.Basics.7.Stacks&Queues

1.Linked Stacks
  A linked stack uses a linked list to store the data in the stack.

template <class Datatype>class LStack : public DLinkedList<Datatype>{public:};

  The head of the list points to the bottom of the stack, and the tail of the list points to the top of the stack.
[Push & Pop & Top] places a new item at the top of the stack;pop an item off the top of the stack.

void Push(Datatype p_data){Append(p_data);}void Pop(){RemoveTail();}void Top(){return m_tail->m_data;}// The top func will not work correctly if the stack is empty.Be careful and make sure that the stack //is not empty before you call this function.int Count(){return m_count;}

 

2.Arrayed Stacks
  It is of a fixed size, but you can use the array's Resize function to make it bigger or smaller as you desire.

template <class Datatype>class AStack : public Array<Datatype>{public:int m_top;// point to the next empty cell};[Cons]AStack(int p_size) : Array<Datatype>(p_size){m_top = 0;}declare a instance:AStack<int> stack(10);

[Push & Pop & Top]

bool Push(Datatype p_data){if (m_size != m_top){m_array[m_top] = p_data;m_top ++;return true;}return false;}void Pop(){if (m_top > 0) m_top --;}Datatype Top(){return m_array[m_top - 1];}int Count(){return m_top;}

3.Linked Queues

template <class Datatype>class LQueue : public DLinkedList<Datatype>{public:void Enqueue(Datatype p_data){Append(p_data);}void Dequeue(){RemoveHead();}Datatype& Front(){return m_head->m_data;}};

4.Arrayed Queues
  For a circular queue, you need 2 new vars: the index of the front of the queue and the number of items within the queue.

template <class Datatype>class AQueue : public Array<Datatype>{public:int m_front;int m_count;};

[Cons & Enqueue]

AQueue(int p_size) : Array<Datatype>(p_size){m_front = 0;m_count = 0;}bool Enqueue(Datatype p_data){if (m_size != m_count){m_array[(m_count + m_front) % m_size] = p_data;m_count ++;return true;}return false;}void Dequeue(){if (m_count > 0){m_count --;m_front ++;if (m_front == m_size)m_front = 0;}}Datatype Front(){return m_array[m_front];}Datatype& operator [] (int p_index){return m_array[(p_index + m_front) % m_size];}