WIll the stack pointer in the function would be formal parameter?

    #include<iostream>
    #include<stdio.h>
    #include<stdlib.h>

    using namespace std;

struct node

{

  int data;

  struct node *next;

};



struct stack

{

node *head;

};

void push(struct stack *stack1,int data)
{

   struct node *new_node= new node;

   new_node->data=data;

   if(stack1->head!=NULL)

   new_node->next=stack1->head;

   else

    new_node->next=NULL;

    stack1->head=new_node;

 }


void pop(struct stack *stack1)

{  

  node *temp= new node;

  if(stack1->head==NULL)

   cout<<"EMPTY"<<endl;

   else

   {

     temp=stack1->head;

     stack1->head=(stack1->head)->next;

     int t;

     t=temp->data;

     free(temp);

     cout<<t<<" ";

   }

}



void show(struct stack *stack1)

{

  node *new_node=new node;

  new_node=stack1->head;

   if(stack1->head==NULL)

  {

    cout<<"EMPTY"<<endl;

    return;

  }

   while(new_node!=NULL)

  {

     cout<<new_node->data<<" ";

     new_node=new_node->next;

  }

}



void peek(struct stack *stack1)

{

   if(stack1->head==NULL)

   cout<<"EMPTY";

   else

   cout<<stack1->head->data<<" ";

}





int main()

{

  int temp,temp2;

  struct stack *stack1=new stack;

  stack1->head=NULL;

  while(1)

  { 

     cin>>temp;

     switch(temp) 

   {

     case 0: exit(0);



     case 1: cin>>temp2;

             cout<<endl;

             push(stack1,temp2);

             break;



     case 2: pop(stack1);

             cout<<endl;

             break;



     case 3: peek(stack1);

             cout<<endl;

             break;



     case 4: show(stack1);

             cout<<endl;

             break;

   }

  }

  return 0;

 }