C07 Answer

/* Puzzle C07 -- fill an array with random doubles in the range Low <= d < High */
double randDoubleRange( double min, double max );

void fillArrayRandomDouble( double arr[], int size,
                            double low, double high )
{
  int j;
  for ( j=0; j < size; j++ )
    arr[j] = randDoubleRange( low, high );
}

double randDoubleRange( double min, double max )
{
  return (rand()*(max-min))/(RAND_MAX+1) + min;
}