C program to find Hexadecimal equivalent using pointer

C program to find Hexadecimal equivalent using pointer

#include < stdio.h >
#include < conio.h > 
#include < alloc.h>

void main()
{
 int num,rem[20],*ptr;
 clrscr();
 printf("\nEnter number:");
 scanf("%d",&num);
 ptr=rem;
 while(num!=0)
 {
  *ptr=num%16;
  num=num/16;
  ptr++;
 }
 ptr--;
 while(ptr>=rem)
 {
  if(*ptr < 10)
   printf("%d",*ptr);
  else
   printf("%c",*ptr+55);
   ptr--;
 }
}