struct person {
  char name[64];
  double height, weight;
};

void swap(struct person *a, struct person *b)
{
  struct person tmp;
  tmp = *a; *a = *b; *b = tmp;
}

void sort_by_height(struct person data[], int size)
{
  int minpos, i, j;
  
  for (i = 0; i < size-1; i++) {
    minpos = i;
    for (j = i+1; j < size; j++) {
      if (data[j].height < data[minpos].height) {
	minpos = j;
      }
    }
    swap(&data[i], &data[minpos]);
  }
}