stack.h

编寫一個Stackf类,包括對該stack的實現

#include<stdlib.h>
enum Error_code{success,overflow,underflow};
template<class T>
class Stack{
	public:
		Stack(int n=20);
		Stack(const Stack<T>& S); //拷贝构造函数
		~Stack();
		Error_code pop();  //弹出(删除)栈顶元素
		Error_code top(T&); //取栈顶元素
		Error_code push(T&); //将数据压入栈中
		void operator=(const Stack<T>&); //重载赋值运算符
		int ele_numbers(){return counter;}; //返回元素个数
		void clear(){counter=0;} //将栈清0
		bool empty();  //栈空则返回true，否则返回false
		bool full();  //栈满则返回true，否则返回false
	private:
		int counter; //当前堆栈元素个数
		int MaxSize; //最大元素个数
		T* stack;
};
template<class T>
Stack<T>::Stack(int n){  //栈初始化
	counter=0;
	MaxSize=n;
	stack=new T[MaxSize];
	if(!stack){  //若stack为空则表明内存不足
		cout<<"NO ENOUGH MEMORY!";
		exit(1);
	}
	return;
}
template<class T>
Stack<T>::Stack(const Stack<T>& S){ //拷贝构造函数
	counter=S.counter;  
	MaxSize=S.MaxSize;
	stack=new T[MaxSize];
	if(!stack){
		cout<<"NO ENOUGH MEMORY!";
		exit(1);
	}
	for(int i=0;i<counter;++i)  //元素逐个复制
		stack[i]=S.stack[i];
	return;
}
template<class T>
Stack<T>::~Stack(){
	delete []stack;
	return;
}
template<class T>
Error_code Stack<T>::pop(){
	if(empty())return underflow; //栈空的情形
	--counter;   //将顶元素删去
	return success;
}
template<class T>
Error_code Stack<T>::top(T& e){
	if(empty())return underflow;  //若栈空时
	e=stack[counter-1];  //用e返回栈顶元素
	return success;
}
template<class T>
Error_code Stack<T>::push(T& e){
	if(full())return overflow; //栈满的情形
	stack[counter++]=e;
	return success;
}
template<class T>
void Stack<T>::operator=(const Stack<T>& another){ //赋值重载
	counter=another.counter;
	MaxSize=another.MaxSize;
	if(!stack) delete []stack; //将原来的栈删去
	stack=new T[MaxSize];
	if(!stack){
		cout<<"NO ENOUGH MEMORY!";
		exit(1);
	}
	for(int i=0;i<counter;++i)  //元素逐个复制
		stack[i]=another.stack[i];
	return;
}
template<class T>
bool Stack<T>::empty(){
	return counter==0;
}
template<class T>
bool Stack<T>::full(){
	return counter==MaxSize;
}