mirror of
https://code.videolan.org/videolan/vlc
synced 2024-09-04 09:11:33 +02:00
![Rémi Denis-Courmont](/assets/img/avatar_default.png)
The standard functions are tdelete, tfind, tsearch and twalk. Testing for non-standard tdestroy does not work properly: it leads to false negative.
256 lines
6.1 KiB
C
256 lines
6.1 KiB
C
/*****************************************************************************
|
|
* tfind.c : implement every t* fuctions
|
|
*****************************************************************************/
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
# include <config.h>
|
|
#endif
|
|
|
|
/** search.h is not present so every t* functions has to be implemented */
|
|
#ifndef HAVE_SEARCH_H
|
|
|
|
#include <assert.h>
|
|
#include <stdlib.h>
|
|
|
|
typedef struct node {
|
|
char *key;
|
|
struct node *llink, *rlink;
|
|
} node_t;
|
|
|
|
/* $NetBSD: tdelete.c,v 1.4 2006/03/19 01:12:08 christos Exp $ */
|
|
|
|
/*
|
|
* Tree search generalized from Knuth (6.2.2) Algorithm T just like
|
|
* the AT&T man page says.
|
|
*
|
|
* The node_t structure is for internal use only, lint doesn't grok it.
|
|
*
|
|
* Written by reading the System V Interface Definition, not the code.
|
|
*
|
|
* Totally public domain.
|
|
*/
|
|
|
|
/* delete node with given key */
|
|
void *
|
|
tdelete(vkey, vrootp, compar)
|
|
const void *vkey; /* key to be deleted */
|
|
void **vrootp; /* address of the root of tree */
|
|
int (*compar) (const void *, const void *);
|
|
{
|
|
node_t **rootp = (node_t **)vrootp;
|
|
node_t *p, *q, *r;
|
|
int cmp;
|
|
|
|
assert(vkey != NULL);
|
|
assert(compar != NULL);
|
|
|
|
if (rootp == NULL || (p = *rootp) == NULL)
|
|
return NULL;
|
|
|
|
while ((cmp = (*compar)(vkey, (*rootp)->key)) != 0) {
|
|
p = *rootp;
|
|
rootp = (cmp < 0) ?
|
|
&(*rootp)->llink : /* follow llink branch */
|
|
&(*rootp)->rlink; /* follow rlink branch */
|
|
if (*rootp == NULL)
|
|
return NULL; /* key not found */
|
|
}
|
|
r = (*rootp)->rlink; /* D1: */
|
|
if ((q = (*rootp)->llink) == NULL) /* Left NULL? */
|
|
q = r;
|
|
else if (r != NULL) { /* Right link is NULL? */
|
|
if (r->llink == NULL) { /* D2: Find successor */
|
|
r->llink = q;
|
|
q = r;
|
|
} else { /* D3: Find NULL link */
|
|
for (q = r->llink; q->llink != NULL; q = r->llink)
|
|
r = q;
|
|
r->llink = q->rlink;
|
|
q->llink = (*rootp)->llink;
|
|
q->rlink = (*rootp)->rlink;
|
|
}
|
|
}
|
|
if (p != *rootp)
|
|
free(*rootp); /* D4: Free node */
|
|
*rootp = q; /* link parent to new node */
|
|
return p;
|
|
}
|
|
|
|
|
|
/* $NetBSD: tdestroy.c,v 1.2 1999/09/16 11:45:37 lukem Exp $ */
|
|
|
|
/*
|
|
* Tree search generalized from Knuth (6.2.2) Algorithm T just like
|
|
* the AT&T man page says.
|
|
*
|
|
* The node_t structure is for internal use only, lint doesn't grok it.
|
|
*
|
|
* Written by reading the System V Interface Definition, not the code.
|
|
*
|
|
* Totally public domain.
|
|
*/
|
|
|
|
/* Walk the nodes of a tree */
|
|
static void
|
|
tdestroy_recurse(node_t* root, void (*free_action)(void *))
|
|
{
|
|
if (root->llink != NULL)
|
|
tdestroy_recurse(root->llink, free_action);
|
|
if (root->rlink != NULL)
|
|
tdestroy_recurse(root->rlink, free_action);
|
|
|
|
(*free_action) ((void *) root->key);
|
|
free(root);
|
|
}
|
|
|
|
void
|
|
tdestroy(vrootp, freefct)
|
|
void *vrootp;
|
|
void (*freefct)(void *);
|
|
{
|
|
node_t *root = (node_t *) vrootp;
|
|
|
|
if (root != NULL)
|
|
tdestroy_recurse(root, freefct);
|
|
}
|
|
|
|
|
|
/* $NetBSD: tfind.c,v 1.5 2005/03/23 08:16:53 kleink Exp $ */
|
|
|
|
/*
|
|
* Tree search generalized from Knuth (6.2.2) Algorithm T just like
|
|
* the AT&T man page says.
|
|
*
|
|
* The node_t structure is for internal use only, lint doesn't grok it.
|
|
*
|
|
* Written by reading the System V Interface Definition, not the code.
|
|
*
|
|
* Totally public domain.
|
|
*/
|
|
|
|
/* find a node, or return 0 */
|
|
void *
|
|
tfind(vkey, vrootp, compar)
|
|
const void *vkey; /* key to be found */
|
|
const void **vrootp; /* address of the tree root */
|
|
int (*compar) (const void *, const void *);
|
|
{
|
|
node_t * const *rootp = (node_t * const*)vrootp;
|
|
|
|
assert(vkey != NULL);
|
|
assert(compar != NULL);
|
|
|
|
if (rootp == NULL)
|
|
return NULL;
|
|
|
|
while (*rootp != NULL) { /* T1: */
|
|
int r;
|
|
|
|
if ((r = (*compar)(vkey, (*rootp)->key)) == 0) /* T2: */
|
|
return *rootp; /* key found */
|
|
rootp = (r < 0) ?
|
|
&(*rootp)->llink : /* T3: follow left branch */
|
|
&(*rootp)->rlink; /* T4: follow right branch */
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
|
|
/* $NetBSD: tsearch.c,v 1.5 2005/11/29 03:12:00 christos Exp $ */
|
|
|
|
/*
|
|
* Tree search generalized from Knuth (6.2.2) Algorithm T just like
|
|
* the AT&T man page says.
|
|
*
|
|
* The node_t structure is for internal use only, lint doesn't grok it.
|
|
*
|
|
* Written by reading the System V Interface Definition, not the code.
|
|
*
|
|
* Totally public domain.
|
|
*/
|
|
|
|
/* find or insert datum into search tree */
|
|
void *
|
|
tsearch(vkey, vrootp, compar)
|
|
const void *vkey; /* key to be located */
|
|
void **vrootp; /* address of tree root */
|
|
int (*compar) (const void *, const void *);
|
|
{
|
|
node_t *q;
|
|
node_t **rootp = (node_t **)vrootp;
|
|
|
|
assert(vkey != NULL);
|
|
assert(compar != NULL);
|
|
|
|
if (rootp == NULL)
|
|
return NULL;
|
|
|
|
while (*rootp != NULL) { /* Knuth's T1: */
|
|
int r;
|
|
|
|
if ((r = (*compar)(vkey, (*rootp)->key)) == 0) /* T2: */
|
|
return *rootp; /* we found it! */
|
|
|
|
rootp = (r < 0) ?
|
|
&(*rootp)->llink : /* T3: follow left branch */
|
|
&(*rootp)->rlink; /* T4: follow right branch */
|
|
}
|
|
|
|
q = malloc(sizeof(node_t)); /* T5: key not found */
|
|
if (q != 0) { /* make new node */
|
|
*rootp = q; /* link new node to old */
|
|
q->key = (void*)vkey; /* initialize new node */
|
|
q->llink = q->rlink = NULL;
|
|
}
|
|
return q;
|
|
}
|
|
|
|
|
|
/* $NetBSD: twalk.c,v 1.2 1999/09/16 11:45:37 lukem Exp $ */
|
|
|
|
/*
|
|
* Tree search generalized from Knuth (6.2.2) Algorithm T just like
|
|
* the AT&T man page says.
|
|
*
|
|
* The node_t structure is for internal use only, lint doesn't grok it.
|
|
*
|
|
* Written by reading the System V Interface Definition, not the code.
|
|
*
|
|
* Totally public domain.
|
|
*/
|
|
|
|
/* Walk the nodes of a tree */
|
|
static void
|
|
twalk_recurse(root, action, level)
|
|
const node_t *root; /* Root of the tree to be walked */
|
|
void (*action) (const void *, VISIT, int);
|
|
int level;
|
|
{
|
|
assert(root != NULL);
|
|
assert(action != NULL);
|
|
|
|
if (root->llink == NULL && root->rlink == NULL)
|
|
(*action)(root, leaf, level);
|
|
else {
|
|
(*action)(root, preorder, level);
|
|
if (root->llink != NULL)
|
|
twalk_recurse(root->llink, action, level + 1);
|
|
(*action)(root, postorder, level);
|
|
if (root->rlink != NULL)
|
|
twalk_recurse(root->rlink, action, level + 1);
|
|
(*action)(root, endorder, level);
|
|
}
|
|
}
|
|
|
|
/* Walk the nodes of a tree */
|
|
void
|
|
twalk(vroot, action)
|
|
const void *vroot; /* Root of the tree to be walked */
|
|
void (*action) (const void *, VISIT, int);
|
|
{
|
|
if (vroot != NULL && action != NULL)
|
|
twalk_recurse(vroot, action, 0);
|
|
}
|
|
|
|
#endif // HAVE_SEARCH_H
|