Hex to Binary digits

Hex to Binary digits

#include <stdio.h>
#include <stdlib.h>
int main()
{
  int i,k;
  int h[4];
  char s;
  
  i=3;
  k=0;
  
  printf("Insert value:");
  scanf(" %c",&s);
  
  if(s>='0' && s<='9')
     k=s-'0';
  else
     k=s-'A'+10;
  
  while (k>0 && i>=0)
  {
     h[i--]=k%2;
     k=k/2;
  }
  
  while(i>=0)
  h[i--]=0;
  
  printf("Hex interpretation of %c is:",s);
  
  for(i=0; i<4; i++)
    printf("%d",h[i]);
  
  printf("\n");
  return 0;
}