debug this code asap

Question

#include<iostream>
using namespace std;
#define max 5
int stack[max] ,top =-1 ;
void push(int);
int pop();

int main()
{ int choice, num;
while(1)
{ cout<<"Enter your choice\n1. push\n2. pop\n3. display\n4.exit\n";
cin>>choice;
switch(choice)
{case 1:{ cout<<"enter a number to be inserted : ";
cin>>num;
push(num);
break;
}
case 2 :{
num = pop();
break;}
case 3:{ void display();
break;
}
case 4:{exit(1);
break;
}
default :
cout<<"invalid choice";
}
}

}

void push(int element)
{ if(top == max-1)
{cout<<"stack overflow\n";
return;
}
top = top+1;
stack[top]=element;
}
int pop()
{ int element;
if(top==-1)
{ cout<<"stack underflow";
return;
}
element = stack[top];
top = top -1;
cout<<"the element that has been deleted is"<<element<<endl;
return element;

}

void display()
{
if(top == -1)
{cout<<"stack is empty\n";
return;
}
cout<<"\n\n";
for(int i=top;i>=0;i++)
{cout<<endl<<stack[i];
}
}

Answer 1

first try to post it in playground