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.\" Japanese Version Copyright (c) 1999 ishikawa, keisuke
.\"         all rights reserved.
.\" Translated Tue Mar  9 08:21:04 JST 1999
.\"         by ishikawa, keisuke <ishikawa@sgk.gr.jp>
.\" Updated & Modified Sun Jan 20 11:31:46 JST 2002
.\"         by Yuichi SATO <ysato@h4.dion.ne.jp>
.\"
.TH TSEARCH 3  2008-09-23 "GNU" "Linux Programmer's Manual"
.SH ̾
tsearch, tfind, tdelete, twalk, tdestroy \- ʬ (binary tree) 
.SH 
.nf
.B #include <search.h>
.sp
.BI "void *tsearch(const void *" key ", void **" rootp ,
.BI "                int (*" compar ")(const void *, const void *));"
.sp
.BI "void *tfind(const void *" key ", const void **" rootp ,
.BI "                int (*" compar ")(const void *, const void *));"
.sp
.BI "void *tdelete(const void *" key ", void **" rootp ,
.BI "                int (*" compar ")(const void *, const void *));"
.sp
.BI "void twalk(const void *" root ", void (*" action ")(const void *" nodep ,
.BI "                                   const VISIT " which ,
.BI "                                   const int " depth "));"
.sp
.B #define _GNU_SOURCE
.br
.B #include <search.h>
.sp
.BI "void tdestroy(void *" root ", void (*" free_node ")(void *" nodep ));
.fi
.SH 
.BR tsearch (),
.BR tfind (),
.BR twalk (),
.BR tdelete ()

ʬڤؿǤ롣
δؿ Knuth (6.2.2) Algorithm T ˴ŤƤ롣
ڹ¤ˤƥΡɤκǽΥեɤϡбǡ
ƥؤΥݥ󥿤Ǥ롣
(ΥǡϡƤӽФץѰդ롣)
\fIcompar\fP ӥ롼ؤΥݥ󥿤Ǥ롣
ӥ롼ϡƥؤΥݥ 2 Ĥ˻ġ
ӥ롼֤ͤϡ1 ܤΥƥब 2 ܤΥƥ
־礭פˤäơ
顢0פͤǤʤФʤʤ
.PP
.BR tsearch ()
ϡڹ¤饢ƥ򸡺ؿǤ롣
\fIkey\fP ϡ륢ƥؤΥݥ󥿤Ǥ롣
\fIrootp\fP ڹ¤κؤΥݥ󥿤ؤΥݥ󥿤Ǥ롣
ڹ¤Ρɤޤޤʤ硢\fIrootp\fP λȤƤѿ
NULL ꤵƤʤФʤʤ
ڹ¤˥ƥबĤä硢
.BR tsearch ()
ϤΥƥؤΥݥ󥿤֤
Ĥʤäϡƥڹ¤ɲä
ɲäƥؤΥݥ󥿤֤
.PP
.BR tfind ()
ϡ
.BR tsearch ()
˻Ƥ뤬
ƥबĤʤä NULL ֤ۤʤ롣
.PP
.BR tdelete ()
ڹ¤饢ƥ롣

.BR tsearch ()
ƱǤ롣
.PP
.BR twalk ()
ϡʬڤ򿼤ͥ (depth-first) ǡ
鱦ˤɤäƤؿǤ롣
\fIroot\fP ϵȤʤΡɤؤΥݥ󥿤Ǥ롣
\fIroot\fP ˺ʳΥΡɤꤹȡʬڤоݤȤʤ롣
.BR twalk ()
ϡΡɤˬ٤
(ĤޤꡢΡɤФƤ 3 դФƤ 1 )
桼ؿ \fIaction\fP ƤӽФ
\fIaction\fP ˤϰʲν 3 ĤΰͿ롣
ǽΰˬ줿ΡɤؤΥݥ󥿤Ǥ롣
2 ܤΰˤϡΡɤξˬ˱
\fBpreorder\fP, \fBpostorder\fP, \fBendorder\fP 
դξ \fBleaf\fP Ϳ롣
(Υܥ \fI<search.h>\fP Ƥ롣)
3 ܤΰϥΡɤοǡξ 0 Ǥ롣
.PP
(Ūˤϡ\fBpreorder\fP, \fBpostorder\fP, \fBendorder\fP 
\fBpreorder\fP, \fBinorder\fP, \fBpostorder\fP ȤΤƤ:
줾졢ǤéǽλǤéä夫 2 ܤλǤé
ǤéäȤȤɽƤ롣
ä \fBpost\%order\fP Ȥ֤̾ΤϾʶ路)
.PP
.BR tdestroy ()
 \fIroot\fP ؤڹ¤Τ
.BR tsearch ()
ؿdzݤ줿꥽Ʋ롣
ڹ¤γƥΡɤˤĤơؿ \fIfree_node\fP ƤӽФ롣
ǡؤΥݥ󥿤δؿΰȤϤ롣
Τ褦ưɬפǤʤС
\fIfree_node\fP ϲ⤷ʤؿؤΥݥ󥿤ǤʤФʤʤ
.SH ֤
.BR tsearch ()
ϡڹ¤˸Ĥäƥफ
ɲäƥؤΥݥ󥿤֤
­ΤᥢƥɲäǤʤä NULL ֤
.BR tfind ()
ϡƥؤΥݥ󥿤֤
פ륢ƥबĤʤ NULL ֤
˰פǤʣ硢֤ͤǤ롣
.PP
.BR tdelete ()
ϺƥοƤؤΥݥ󥿤֤
ƥबĤʤä NULL ֤
.PP
\fIrootp\fP  NULL ξ硢
.BR tsearch (),
.BR tfind (),
.BR tdelete ()
 NULL ֤
.SH 
SVr4, POSIX.1-2001.
ؿ
.BR tdestroy ()
 GNU γĥǤ롣
.SH 
.BR twalk ()
ϺؤΥݥ󥿤ˤȤ뤬
ۤδؿϺؤΥݥ󥿤ؤΥݥ󥿤Ǥ롣
.PP
.BR twalk ()
ˤƤϡ\fBpostorder\fP 
ֺʬڤθǡʬڤפ̣Ƥ롣
ͤˤäƤϤ "inorder" ȸƤǡ
"postorder" ξʬڤθפȤ⤢롣
.PP
.BR tdelete ()
ϡΡɤλѤƤ뤬
ΡɤбǡΥϡ桼ʤФʤʤ
.PP
Υץϡ桼ؿ "endorder"  "leaf" ˤ
ƤӽФưʹߤϡ
.BR twalk ()
ΥΡɤ򻲾ȤʤȤȤƤ롣
 GNU 饤֥μǤϵǽ뤬System V Υޥ˥奢ˤ¸ߤʤ
.SH 
ʲΥץ 12 Ĥʬڤ塢
֤˽Ϥ (κݡʣ 1 ĤˤޤȤ)
.sp
.nf
#define _GNU_SOURCE     /* Expose declaration of tdestroy() */
#include <search.h>
#include <stdlib.h>
#include <stdio.h>
#include <time.h>

void *root = NULL;

void *
xmalloc(unsigned n)
{
    void *p;
    p = malloc(n);
    if (p)
        return p;
    fprintf(stderr, "insufficient memory\\n");
    exit(EXIT_FAILURE);
}

int
compare(const void *pa, const void *pb)
{
    if (*(int *) pa < *(int *) pb)
        return \-1;
    if (*(int *) pa > *(int *) pb)
        return 1;
    return 0;
}

void
action(const void *nodep, const VISIT which, const int depth)
{
    int *datap;

    switch (which) {
    case preorder:
        break;
    case postorder:
        datap = *(int **) nodep;
        printf("%6d\\n", *datap);
        break;
    case endorder:
        break;
    case leaf:
        datap = *(int **) nodep;
        printf("%6d\\n", *datap);
        break;
    }
}

int
main(void)
{
    int i, *ptr;
    void *val;

    srand(time(NULL));
    for (i = 0; i < 12; i++) {
        ptr = (int *) xmalloc(sizeof(int));
        *ptr = rand() & 0xff;
        val = tsearch((void *) ptr, &root, compare);
        if (val == NULL)
            exit(EXIT_FAILURE);
        else if ((*(int **) val) != ptr)
            free(ptr);
    }
    twalk(root, action);
    tdestroy(root, free);
    exit(EXIT_SUCCESS);
}
.fi
.SH Ϣ
.BR bsearch (3),
.BR hsearch (3),
.BR lsearch (3)
.BR qsort (3),
.BR feature_test_macros (7)