e54e4d47f1
* mingwex/tfind.c: New file. * mingwex/tdelete.c: New file. * mingwex/tsearch.c: New file. * mingwex/twalk.c: New file. * mingwex/Makefile.in (DISTFILES): Add tsearch.c twalk.c tdelete.c tfind.c. * mingwex/Makefile.in (POSIX_OBJS): Add tsearch.o twalk.o tdelete.o tfind.o. * include/search.h (tfind): Declare. (tdelete): Declare. (tsearch): Declare. (twalk): Declare. (ENTRY): Define. (ACTION): Define. (VISIT): Define. (node_t): Define, on condition of _SEARCH_PRIVATE.
42 lines
952 B
C
Executable File
42 lines
952 B
C
Executable File
/* $NetBSD: tfind.c,v 1.3.18.2 2005/03/23 11:12:21 tron Exp $ */
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/*
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* Tree search generalized from Knuth (6.2.2) Algorithm T just like
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* the AT&T man page says.
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*
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* The node_t structure is for internal use only, lint doesn't grok it.
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*
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* Written by reading the System V Interface Definition, not the code.
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*
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* Totally public domain.
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*/
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#include <assert.h>
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#define _SEARCH_PRIVATE
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#include <stdlib.h>
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#include <search.h>
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/* find a node, or return 0 */
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void *
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tfind(const void *vkey,
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void * const *vrootp,
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int (*compar) (const void *, const void *))
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{
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node_t * const *rootp = (node_t * const*)vrootp;
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if (rootp == NULL)
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return NULL;
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while (*rootp != NULL) { /* T1: */
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int r;
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if ((r = (*compar)(vkey, (*rootp)->key)) == 0) /* T2: */
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return *rootp; /* key found */
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rootp = (r < 0) ?
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&(*rootp)->llink : /* T3: follow left branch */
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&(*rootp)->rlink; /* T4: follow right branch */
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}
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return NULL;
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}
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