min 栈

#include <iostream>
using namespace std;


#define  MIN(a,b) ((a)<(b)?(a):(b))


struct Node{
int m_min;
int value;
Node *next;
};


class Stack{
private:
Node *pTop;
public:
Stack();
~Stack();
int pop();
bool push(int);
int min();
};


Stack::Stack()
{
pTop = NULL;
}
Stack::~Stack()
{
if (NULL == pTop)
{
return ;
}
while (pTop)
{
Node *temp = pTop;
pTop = pTop->next;
delete temp;
}
}


bool Stack::push(int value)
{
if (pTop ==NULL)
{
pTop = new Node();
pTop->next=NULL;
pTop->m_min=value;
pTop->value = value;
}
else
{
Node *node = new Node();
node->value = value;
node->next = pTop;
node->m_min=MIN(pTop->m_min,value);
pTop=node;
}
return true;
}


int Stack::pop()
{
if (NULL == pTop)
{
return -1;
}
Node *temp = pTop;
int value = pTop->value;
pTop = pTop->next;
delete temp;
return value;
}


int Stack::min()
{
if (NULL == pTop)
{
return -1;
}
return pTop->m_min;
}


int main()
{
int num;
Stack mystack;
cin >> num;
while (-1 != num)
{
mystack.push(num);
cin >> num;
}
cout<<"The min value is:"<<mystack.min()<<endl;  
mystack.pop();  
mystack.pop();  
cout<<"The min value is:"<<mystack.min()<<endl;  
return 0;  
}