3 Stack - Linked List

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

using namespace std;

void push();
void pop();
void display();


struct node
{
int info;
struct node *link;
} *top=NULL;

int main()
{
int choice;

 do
 {
 cout<<"\n\n1.Push\n";
 cout<<"2.Pop\n";
 cout<<"3.Display\n";
 cout<<"4.Quit\n";
 cout<<"Enter your choice : ";
 cin>>choice;

  switch(choice)
  {
  case 1:push();break;
  case 2:pop();break;
  case 3:display();break;
  case 4:exit(1);
  default :cout<<"Wrong choice\n";
  }
 }while(choice!=4);
return 0;
}

void push()
{
struct node *tmp;
int pushed_item;

tmp = (struct node *)malloc(sizeof(struct node));

cout<<"Value to Push:";
cin>>pushed_item;

tmp->info=pushed_item;
tmp->link=top;
top=tmp;
}

void pop()
{
struct node *tmp;
 if(top == NULL)
 cout<<"Stack is empty\n";
 else
 {
 tmp=top;
 cout<<"Popped item is "<<tmp->info;
 top=top->link;
 free(tmp);
 }
}

void display()
{
struct node *ptr;
ptr=top;
 if(top==NULL)
 cout<<"Stack is empty\n";
 else
 {
 cout<<"Stack elements :\n";
  while(ptr!= NULL)
  {
  cout<<"\n"<<ptr->info;
  ptr = ptr->link;
  }
 }
}