queue.h
#include<iostream>
#include<assert.h>
using namespace std;
template<typename T>
struct Node
{
template<class T>
friend class Queue;
public:
Node(const T& x)
:_data(x)
, _next(NULL)
{}
private:
T _data;
Node* _next;
};
template<class T>
class Queue
{
public:
Queue()
:_QHead(NULL)
, _QTail(NULL)
{}
~Queue()
{
while (_size != 0)
{
Node<T>* del = _QHead;
_QHead = _QHead->_next;
delete del;
_size--;
}
}
void Push(const T& x) //隊尾插入元素
{
assert(this);
if (_QHead == NULL)
{
_QHead = new Node<T>(x);
_QTail = _QHead;
}
else
{
Node<T>* tmp = new Node<T>(x);
_QTail->_next = tmp;
_QTail = tmp;
}
_size++;
}
void Pop() //隊頭刪除元素
{
assert(this);
if (_QHead == NULL) //鏈表爲空
{
return;
}
if (_QHead == _QTail) //只有一個節點
{
delete _QHead;
_QHead = NULL;
_QTail = NULL;
}
else //有多個節點
{
Node<T>* del = _QHead;
_QHead = _QHead->_next;
delete del;
}
_size--;
}
bool Empty() //判空
{
return _size == 0;
}
int Size() //返回隊列長度
{
return _size;
}
const T& Fornt() //返回隊頭元素
{
return _QHead->_data;
}
const T& Back() //返回隊尾元素
{
return _QTail->_data;
}
private:
Node<T>* _QHead;
Node<T>* _QTail;
size_t _size;
};
main.cpp
#include"queue.h"
template<class T>
class Stack
{
public:
Queue<T>* EmptyQ = &_p1; //指向空隊列的指針
Queue<T>* NonEmptyQ = &_p2; //指向非空隊列的指針
void Swap()
{
if (!EmptyQ->Empty()) //如果p1隊列不爲空,交換兩個指針變量的值
{
swap(EmptyQ, NonEmptyQ);
}
}
void Push(const T& x) //哪個隊列不是空的就往哪個隊列插
{
Swap();
NonEmptyQ->Push(x);
_size++;
}
void Pop()
{
Swap();
size_t size = _size;
while (size > 1) //把前_size - 1個數,挪到另外一個隊列
{
T tmp = NonEmptyQ->Fornt();
EmptyQ->Push(tmp);
NonEmptyQ->Pop();
size--;
}
NonEmptyQ->Pop(); //刪除最後一個元素
_size--;
}
bool Empty()
{
return _size == 0;
}
int Size()
{
return _size;
}
const T& Top()
{
Swap();
return NonEmptyQ->Back();
}
private:
Queue<T> _p1;
Queue<T> _p2;
size_t _size;
};
void Test()
{
Stack<int> s1;
s1.Push(1);
s1.Push(2);
s1.Push(3);
s1.Pop();
s1.Push(4);
s1.Top();
s1.Pop();
s1.Pop();
s1.Pop();
}
int main()
{
Test();
getchar();
return 0;
}