From c6ef89664b8c0d7aa85bddd5c7014aa6df82cbe7 Mon Sep 17 00:00:00 2001 From: tcsullivan Date: Sat, 17 Nov 2018 13:02:57 -0500 Subject: added pdclib, removed sash --- src/pdclib/functions/stdlib/bsearch.c | 61 +++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 src/pdclib/functions/stdlib/bsearch.c (limited to 'src/pdclib/functions/stdlib/bsearch.c') diff --git a/src/pdclib/functions/stdlib/bsearch.c b/src/pdclib/functions/stdlib/bsearch.c new file mode 100644 index 0000000..211c55c --- /dev/null +++ b/src/pdclib/functions/stdlib/bsearch.c @@ -0,0 +1,61 @@ +/* bsearch( const void *, const void *, size_t, size_t, int(*)( const void *, const void * ) ) + + This file is part of the Public Domain C Library (PDCLib). + Permission is granted to use, modify, and / or redistribute at will. +*/ + +#include + +#ifndef REGTEST + +void * bsearch( const void * key, const void * base, size_t nmemb, size_t size, int (*compar)( const void *, const void * ) ) +{ + const void * pivot; + int rc; + size_t corr; + while ( nmemb ) + { + /* algorithm needs -1 correction if remaining elements are an even number. */ + corr = nmemb % 2; + nmemb /= 2; + pivot = (const char *)base + (nmemb * size); + rc = compar( key, pivot ); + if ( rc > 0 ) + { + base = (const char *)pivot + size; + /* applying correction */ + nmemb -= ( 1 - corr ); + } + else if ( rc == 0 ) + { + return (void *)pivot; + } + } + return NULL; +} + +#endif + +#ifdef TEST + +#include "_PDCLIB_test.h" + +static int compare( const void * left, const void * right ) +{ + return *( (unsigned char *)left ) - *( (unsigned char *)right ); +} + +int main( void ) +{ + TESTCASE( bsearch( "e", abcde, 4, 1, compare ) == NULL ); + TESTCASE( bsearch( "e", abcde, 5, 1, compare ) == &abcde[4] ); + TESTCASE( bsearch( "a", abcde + 1, 4, 1, compare ) == NULL ); + TESTCASE( bsearch( "0", abcde, 1, 1, compare ) == NULL ); + TESTCASE( bsearch( "a", abcde, 1, 1, compare ) == &abcde[0] ); + TESTCASE( bsearch( "a", abcde, 0, 1, compare ) == NULL ); + TESTCASE( bsearch( "e", abcde, 3, 2, compare ) == &abcde[4] ); + TESTCASE( bsearch( "b", abcde, 3, 2, compare ) == NULL ); + return TEST_RESULTS; +} + +#endif -- cgit v1.2.3