int hdist(int c[r],int a,int b)
{
  int i;
  int count=0;
  int dist=c[a]^c[b];

  for(i=0;i<n;i++) if(dist & (1<<i))count++;
  printf("%d ",count);
  return count;

}


Tried this, and it works here. Peter C.

#include <stdio.h>

int n = 8;
int r = 2;

int hdist(int c[r],int a,int b)
{
  int i;
  int count=0;
  int dist=c[a]^c[b];

  for(i=0;i<n;i++) if(dist & (1<<i)) count++;
  printf("%d\n",count);
  return count;

}

int main( int argc, char **argv )
{
  int a[2] = { 0xF0, 0x00 };

  hdist(a, 0, 1);
}