Array representation of stack

arraystack.c

#include<stdio.h>
#define MAX 100;
int top=-1,stack[100];
void push(int item,int n)
{
      if(top==n-1)
          printf("\n stack overflow");
      else
        {
          top=top+1;
          stack[top]=item;
        }
}
void pop()
{
        int temp;
        if(top==-1)
          printf("\n stack underflow");
        else
        {
           temp=stack[top];
          top=top-1;
          }
   }
void display(int n)
{
        for(int i=0;i<=top;i++)
        {
          printf("\n%d",stack[i]);
        }
}
int main()
{
  
  int n,item,ch;
 printf("\n enter size");
  scanf("%d",&n);
  printf("\n1push\n2pop\n3display");
  while(1){
  printf("\n enter choice");
  scanf("%d",&ch);
  switch(ch)
  {
    case 1:
    {
    printf("enter number");
    scanf("%d",&item);
    push(item,n);
    break;
    }
    case 2:
    {
      pop();
      break;
    }
    case 3:
    {
      display(n);
      break;
    }
    default:
    printf("\n invalid choice");
    break;
  }
  
  
 }
 }