Decimal to Binary Conversion using Stack in C++

#include<iostream.h>

#include<conio.h>

class stack{

private:

int top,max;

int *stackarr;

public:

stack()

{

cout<<"\nEnter the size of stack: ";

cin>>max;

top=-1;

}

void push(int n)

{

if(top==max)

cout<<"\nStack is full\n";

else

top=top+1;

stackarr[top]=n;

}

int pop()

{

if(top==-1)

cout<<"\nStack is empty\n";

else

top=top-1;

return stackarr[top+1];

}

void decimal(int num)

{

cout<<"\n\nThe decimal to binery convertion of "<<num<<" is Below.\n ";

   for(num;num>0;num=num/2)

  {  push(num%2);       }

while(top!=-1)

  { cout<<pop()<<" ";   }

}

};

void main()

{

clrscr();

int value=0;

stack obj;

cout<<"\nEnter a number in Decimal notaion : ";

cin>>value;

obj.decimal(value);

getch();

}