qsort() to sort an array of structures

#include 
#include 
#include 

/* Define an array of critters to sort.  */

struct critter
{
  char *name;
  char *species;
};

struct critter muppets[]=
{
  {"Kermit", "frog"},
  {"Piggy", "pig"},
  {"Gonzo", "whatever"},
  {"Fozzie", "bear"},
  {"Sam", "eagle"},
  {"Robin", "frog"},
  {"Animal", "animal"},
  {"Camilla", "chicken"},
  {"Sweetums", "monster"},
  {"Dr. Strangepork", "pig"},
  {"Link Hogthrob", "pig"},
  {"Zoot", "human"},
  {"Dr. Bunsen Honeydew", "human"},
  {"Beaker", "human"},
  {"Swedish Chef", "human"}};

int count = sizeof (muppets) / sizeof (struct critter);



/* This is the comparison function used for sorting and searching.  */

int 
critter_cmp (const struct critter *c1, const struct critter *c2)
{
  return strcmp (c1->name, c2->name);
}


/* Print information about a critter.  */

void 
print_critter (const struct critter *c)
{
  printf ("%s, the %s\n", c->name, c->species);
}


/* Do the lookup into the sorted array.  */

void 
find_critter (char *name)
{
  struct critter target, *result;
  target.name = name;
  result = bsearch (&target, muppets, count, sizeof (struct critter),
		    critter_cmp);
  if (result)
    print_critter (result);
  else
    printf ("Couldn't find %s.\n", name);
}

/* Main program.  */

int
main (void)
{
  int i;

  for (i = 0; i < count; i++)
    print_critter (&muppets[i]);
  printf ("\n");

  qsort (muppets, count, sizeof (struct critter), critter_cmp);

  for (i = 0; i < count; i++)
    print_critter (&muppets[i]);
  printf ("\n");

  find_critter ("Kermit");
  find_critter ("Gonzo");
  find_critter ("Janice");

  return 0;
}

원본URL


qsort(dDocs, DocCnt, sizeof(DOCSIM), (void *)desc);

/* 해당 문서를 내림차순(DESC) 으로 정렬 */
int desc(DOCSIM_DIS *p1, DOCSIM_DIS *p2)
{
return p1->Distance - p2->Distance;
}

/* 해당 문서를 오름차순(ASC) 으로 정렬 */
int asc(DOCSIM_DIS *p1, DOCSIM_DIS *p2)
{
return p2->Distance - p1->Distance;
}