mirror of https://github.com/TheAlgorithms/C
55 lines
1.1 KiB
C
55 lines
1.1 KiB
C
/**
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* @addtogroup hash Hash algorithms
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* @{
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* @file hash_adler32.c
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* @author [Christian Bender](https://github.com/christianbender)
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* @brief 32-bit [Adler hash](https://en.wikipedia.org/wiki/Adler-32) algorithm
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*/
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#include <assert.h>
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#include <inttypes.h>
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#include <stdio.h>
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/**
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* @brief 32-bit Adler algorithm implementation
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*
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* @param s NULL terminated ASCII string to hash
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* @return 32-bit hash result
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*/
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uint32_t adler32(const char* s)
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{
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uint32_t a = 1;
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uint32_t b = 0;
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const uint32_t MODADLER = 65521;
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size_t i = 0;
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while (s[i] != '\0')
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{
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a = (a + s[i]) % MODADLER;
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b = (b + a) % MODADLER;
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i++;
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}
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return (b << 16) | a;
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}
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/**
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* @brief Test function for ::adler32
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* \returns None
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*/
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void test_adler32()
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{
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assert(adler32("Hello World") == 403375133);
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assert(adler32("Hello World!") == 474547262);
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assert(adler32("Hello world") == 413860925);
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assert(adler32("Hello world!") == 487130206);
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printf("Tests passed\n");
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}
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/** @} */
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/** Main function */
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int main()
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{
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test_adler32();
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return 0;
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}
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