Stack using Linked List

#include<bits/stdc++.h>
using namespace std;
struct Node
{
   int data;
   struct Node *next;
}*top=NULL;

void push(int x)
{
    struct Node *t;;
    t=(struct Node*)nalloc(sizeof(struct Node));
    

     t->data=x;
     t->next=top;
     top=T;
         
  }  
  
  int pop()
  {
       int x=-1;
       struct Node *t;
       if (top==NULL)
          printf("Stack is Empty");
       else
         {
         t=top;
         x=t->data;
         top=t->next;
         free(t);
         }
       return x;
  }   
  
  
  void Display()
  {
      struct Node *p;
      p=top;
      while(p!=NULL)
      {
      printf("%d",p->data);
      p=p->next;
      }
      
   }   
  }      
int main()
{
push(10);                                  //Here i do not need to create an object of the structure as I have declared Top as a global variable and there we do not even need to pass it to the functions as a parameter
Display();
pop();
}