Error Correction Question

Correct following program.

The function sort_by_height sorts an array of the structure person in ascending order,
which represents a personal physical datum for each person. 


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

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

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

Result