aqueue.h

对底层队列的一个实现

//AQueue.h
template <class Elem>
class AQueue
{
private:
	Elem* arrayQueue;
	int size;
	int front;
	int rear;
public:
	AQueue(int sz = 100)
	{
		size = sz + 1;
		arrayQueue = new Elem[size];
		front = rear = 0;
	}
	~AQueue()
	{
		delete [] arrayQueue;
	}

	void Clear()
	{
		//可以不赋0
		front = rear;
	}
	bool Push(const Elem& a)
	{
		if((rear + 1) % size == front)
		{
			cerr << "Error:the queue is full!" << endl;
			return false;
		}
		arrayQueue[rear++] = a;
		rear %= size;
		return true;
	}

	Elem Front()const
	{
		if(front == rear)
		{
			cerr << "Error:nothing in queue,top failed!" << endl;
			return (Elem)0;
		}
		return arrayQueue[front];
	}

	bool Front(Elem& value)
	{
		if(front == rear)
		{
			cerr << "Error:nothing in queue,top failed!" << endl;
			return false;
		}
		value = arrayQueue[front];
		return true;
	}

	bool Pop()
	{
		if(front == rear)
		{
			cerr << "Error:nothing in queue,pop failed!" << endl;
			return false;
		}
		//代码精简
		front = (front + 1) % size;
		return true;
	}

	bool Empty()const
	{
		if(front == rear)
			return true;
		else
			return false;
	}

	int Size()const
	{
		return (rear + size - front) % size;
	}

	bool Back(Elem& value)
	{
		if(front == rear)
		{
			cerr << "Error:nothing in queue,back failed!" << endl;
			return false;
		}
		value = arrayQueue[rear - 1];
		return true;
	}

	Elem Back()const
	{
		if(front == rear)
		{
			cerr << "Error:nothing in queue,back failed!" << endl;
			return (Elem)0;
		}
		return arrayQueue[rear - 1];
	}
};