49 lines
1.4 KiB
C
49 lines
1.4 KiB
C
/* Copyright (C) 1991,92,97,2000,02 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <stdlib.h>
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/* Perform a binary search for KEY in BASE which has NMEMB elements
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of SIZE bytes each. The comparisons are done by (*COMPAR)(). */
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void *
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bsearch (const void *key, const void *base, size_t nmemb, size_t size,
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int (*compar) (const void *, const void *))
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{
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size_t l, u, idx;
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const void *p;
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int comparison;
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l = 0;
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u = nmemb;
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while (l < u)
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{
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idx = (l + u) / 2;
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p = (void *) (((const char *) base) + (idx * size));
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comparison = (*compar) (key, p);
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if (comparison < 0)
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u = idx;
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else if (comparison > 0)
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l = idx + 1;
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else
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return (void *) p;
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}
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return NULL;
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}
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libc_hidden_def (bsearch)
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