c++ 用队列 实现简单 stack

#include "iostream"
using namespace std;

class linknode
{
public:
 linknode *next;
 int value;
 linknode();
};

linknode::linknode()
{
 next = NULL;
 value = -1;
}
class linklist
{
public:
 linknode *head;
 int count;
};
class Stack
{
public:
 linklist list;
 Stack();
 void push(linknode *node);
 void pop(linknode *node);
 void show();
 bool exsit(int value);
 void clear();
};

Stack::Stack()
{
 list.count =0;
 list.head = new linknode;
}
void Stack::push(linknode *node)
{
 linknode *temp = list.head;
 if (!temp->next)
 {
  temp->next = node;
  list.count ++;
 }
 else
 {
  node->next =temp->next; 
  list.head->next = node;
  list.count ++;

 }
 cout <<"node value"<<node->value<<endl;
}

void Stack::pop(linknode *node)
{
 linknode *temp =list.head;
 linknode *prenode;
 while(temp->next)
 {
  prenode = temp;
  temp = temp->next;
  if (node->value == temp->value)
  {
    linknode *nextnode = temp->next;
    prenode->next = nextnode;
    cout<<"DELETE VALUE  "<<node->value<<endl;
    delete temp;
    this->list.count --;
    return;
  }
 }
 cout<<"NOT FOUND"<<endl;
 return;
}
void Stack::show()
{
 linknode *temp =list.head;

 while(temp->next)
 {
  temp = temp->next;
  cout<<temp->value;
 }
 return;
}
bool Stack::exsit(int value)
{
 linknode *temp =list.head;
 bool flag =false;
 while(temp->next)
 {
  temp =temp->next;
  if (temp->value == value)
  {
   cout<<value<<" EXIST"<<endl;
   flag = true;
  }
 }
 return flag;
}

void Stack::clear()
{
 linknode *temp =list.head->next;
 
 linknode *current;
    while(temp)
 {
  current = temp;
  temp = temp->next;
  cout<<"value "<<current->value<<" DELETED "<<endl;
  delete current;
  list.count --;
 }
}
int main()
{
 Stack s;
 for (int i=0;i<10;i++)
 {
  linknode *node = new linknode;
  node->value = i;
  s.push(node);
 }

 linknode *unused = new linknode;
 unused->value = 0;
 s.pop(unused);
 s.show();
 if (s.exsit(5))
 {
  cout<<"FOUND"<<endl;
 }
 s.clear();
 return 0;
}