模板实现简易stack

/*cpp*/
s.empty()        //如果栈为空返回true，否则返回false
s.size()                 //返回栈中元素个数
s.pop()                  //删除栈顶元素，但不返回其值
s.top()                  //返回栈顶元素，但不删除元素
s.push()                 //在栈顶压入新元素

/*Stack.cpp*/

#include <iostream>
using namespace std;

template <class T>
class SeqList
{
public:
SeqList()
:_data(NULL)
,_size(0)
,_capacity(0)
{
CheckCapacity();
}
~SeqList()
{
if(_data != NULL)
{
delete[] _data;
}
}
public:
void Display() const
{
int i = 0;
for(i; i<_size; i++)
{
cout<<_data[i]<<" ";
}
cout<<"over"<<endl;
}
void CheckCapacity()
{
if(_size == _capacity)
{
T* tmp = new T[_capacity+3];
memcpy(tmp, _data, (_capacity)*sizeof(T));
delete[] _data;
_data = tmp;
_capacity = _capacity+3;
}
}
void PushBack(const T& d)
{
CheckCapacity();
_data[_size] = d;
_size++;
}
void PopBack()
{
if(_size == 0)
{
cout<<"Stack is empty!!"<<endl;
return;
}
_size--;
}
int GetSize()
{
return _size;
}
T& retTop() const
{
if(_data == NULL)
{
cout<<"Stack is empty!!"<<endl;
exit(1);
}
return _data[_size-1];
}
bool retEmpty() const
{
if(_data == NULL)
{
return false;
}
return true;
}
protected:
int _size ;
int _capacity ;
T* _data ;
};
template <class T, class Container >
class Stack
{
public :
void Push(const T& x)
{
_con.PushBack(x);
}
void Pop()
{
_con.PopBack();
}
int Size()
{
return _con.GetSize();
}
const T& Top()
{
return _con.retTop();
}
bool Empty()
{
return _con.retEmpty();
}
void Show()
{
_con.Display();
}
private:
Container _con;
};

int main()
{
Stack<int, SeqList<int>> stack1;
stack1.Push(1);
stack1.Push(2);
stack1.Push(3);
stack1.Push(4);
stack1.Push(5);
stack1.Show();
stack1.Pop();
stack1.Show();
int ret = stack1.Top();
cout<<ret<<endl;
bool result = stack1.Empty();
cout<<result<<endl;
int size = stack1.Size();
cout<<size<<endl;
system("pause");
return 0;
}