基于线性表的堆栈

#ifndef IOSTREAM
#include <iostream>
#endif

template<class T>
class Stack
{
public:
	Stack(int MaxSize=10);
	~Stack();
	bool IsEmpty()const{return top==0;}
	bool IsFull()const{return top==MaxTop;}
	T Top()const;
	Stack<T>&Add(const T &x);
	Stack<T>&Delete(T&x);

	int GetStackSize()const;//确定堆栈的大小 
private:
	int top;
	int MaxTop;
	T *stack;//堆栈元素数组
};

//构造函数
template<class T>
Stack<T>::Stack(int MaxSize)
{
	MaxTop=MaxSize-1;
	stack=new T [MaxSize];
	top=-1;//因为top=0的时候等于已经有一个元素了，所以这里为-1
}
//析构函数
template<class T>
Stack<T>::~Stack()
{
	delete [] stack;
}
//弹出栈顶
template<class T>
T Stack<T>::Top()const
{
	if(IsEmpty()) throw OutOfBounds();
	else
	return stack[top];
}
//压入栈
template<class T>
Stack<T>&Stack<T>::Add(const T &x)
{
	if(IsFull())
		throw NoMem();
	top++;
	stack[top]=x;
	return *this;
}

//弹出栈
template<class T>
Stack<T>&Stack<T>::Delete(T&x)
{
	if((IsEmpty()))
		throw OutOfBounds();
	x=stack[top];
	top--;
	return *this;
}

//确定堆栈的大小 
template<class T>
int Stack<T>::GetStackSize()const
{
	if(IsEmpty())
		throw OutOfBounds();
	int len=top;
	return ++len;
}