java Hash算法大全.docx

1、java Hash算法大全java Hash算法大全Java代码 /* Hash算法大全* 推荐使用FNV1算法* algorithm None* author Goodzzp 2006-11-20* lastEdit Goodzzp 2006-11-20* editDetail Create*/ public class HashAlgorithms /*/* 加法hash* param key 字符串* param prime 一个质数* return hash结果*/ public static int additiveHash(String key, int prime) int ha

2、sh, i; for (hash = key.length(), i = 0; i key.length(); i+) hash += key.charAt(i); return (hash % prime); /*/* 旋转hash* param key 输入字符串* param prime 质数* return hash值*/ public static int rotatingHash(String key, int prime) int hash, i; for (hash=key.length(), i=0; ikey.length(); +i) hash = (hash28)key

3、.charAt(i); return (hash % prime); / return (hash (hash10) (hash20); / 替代： / 使用：hash = (hash (hash10) (hash20) & mask; / 替代：hash %= prime; /*/* MASK值，随便找一个值，最好是质数*/ static int M_MASK = 0x8765fed1; /*/* 一次一个hash* param key 输入字符串* return 输出hash值*/ public static int oneByOneHash(String key) int hash, i

4、; for (hash=0, i=0; ikey.length(); +i) hash += key.charAt(i); hash += (hash 6); hash += (hash 11); hash += (hash 15); / return (hash & M_MASK); return hash; /*/* Bernsteins hash* param key 输入字节数组* param level 初始hash常量* return 结果hash*/ public static int bernstein(String key) int hash = 0; int i; for

5、(i=0; ikey.length(); +i) hash = 33*hash + key.charAt(i); return hash; / /*/ Pearsons Hash / char pearson(charkey, ub4 len, char tab256) / / char hash; / ub4 i; / for (hash=len, i=0; ilen; +i) / hash=tabhashkeyi; / return (hash); / /*/ CRC Hashing，计算crc,具体代码见其他 / ub4 crc(char *key, ub4 len, ub4 mask,

6、 ub4 tab256) / / ub4 hash, i; / for (hash=len, i=0; i 8) tab(hash & 0xff) keyi; / return (hash & mask); / /*/* Universal Hashing*/ public static int universal(charkey, int mask, int tab) int hash = key.length, i, len = key.length; for (i=0; i(len3; if (k&0x01) = 0) hash = tabi+0; if (k&0x02) = 0) ha

7、sh = tabi+1; if (k&0x04) = 0) hash = tabi+2; if (k&0x08) = 0) hash = tabi+3; if (k&0x10) = 0) hash = tabi+4; if (k&0x20) = 0) hash = tabi+5; if (k&0x40) = 0) hash = tabi+6; if (k&0x80) = 0) hash = tabi+7; return (hash & mask); /*/* Zobrist Hashing*/ public static int zobrist( char key,int mask, int

8、tab) int hash, i; for (hash=key.length, i=0; i M_SHIFT) & M_MASK; /*/* 改进的32位FNV算法1* param data 数组* return int值*/ public static int FNVHash1(byte data) final int p = 16777619; int hash = (int)2166136261L; for(byte b:data) hash = (hash b) * p; hash += hash 7; hash += hash 17; hash += hash 5; return h

9、ash; /*/* 改进的32位FNV算法1* param data 字符串* return int值*/ public static int FNVHash1(String data) final int p = 16777619; int hash = (int)2166136261L; for(int i=0;idata.length();i+) hash = (hash data.charAt(i) * p; hash += hash 7; hash += hash 17; hash += hash 5; return hash; /*/* Thomas Wang的算法，整数hash*

10、/ public static int intHash(int key) key += (key 10); key += (key 6); key += (key 16); return key; /*/* RS算法hash* param str 字符串*/ public static int RSHash(String str) int b = 378551; int a = 63689; int hash = 0; for(int i = 0; i str.length(); i+) hash = hash * a + str.charAt(i); a = a * b; return (h

11、ash & 0x7FFFFFFF); /*/* End Of RS Hash Function */ /*/* JS算法*/ public static int JSHash(String str) int hash = 1315423911; for(int i = 0; i str.length(); i+) hash = (hash 2); return (hash & 0x7FFFFFFF); /*/* End Of JS Hash Function */ /*/* PJW算法*/ public static int PJWHash(String str) int BitsInUnsi

12、gnedInt = 32; int ThreeQuarters = (BitsInUnsignedInt * 3) / 4; int OneEighth = BitsInUnsignedInt / 8; int HighBits = 0xFFFFFFFF (BitsInUnsignedInt - OneEighth); int hash = 0; int test = 0; for(int i = 0; i str.length();i+) hash = (hash ThreeQuarters) & (HighBits); return (hash & 0x7FFFFFFF); /*/* En

13、d Of P. J. Weinberger Hash Function */ /*/* ELF算法*/ public static int ELFHash(String str) int hash = 0; int x = 0; for(int i = 0; i str.length(); i+) hash = (hash 24); hash &= x; return (hash & 0x7FFFFFFF); /*/* End Of ELF Hash Function */ /*/* BKDR算法*/ public static int BKDRHash(String str) int see

14、d = 131; / 31 131 1313 13131 131313 etc. int hash = 0; for(int i = 0; i str.length(); i+) hash = (hash * seed) + str.charAt(i); return (hash & 0x7FFFFFFF); /*/* End Of BKDR Hash Function */ /*/* SDBM算法*/ public static int SDBMHash(String str) int hash = 0; for(int i = 0; i str.length(); i+) hash = s

15、tr.charAt(i) + (hash 6) + (hash 16) - hash; return (hash & 0x7FFFFFFF); /*/* End Of SDBM Hash Function */ /*/* DJB算法*/ public static int DJBHash(String str) int hash = 5381; for(int i = 0; i str.length(); i+) hash = (hash 5) + hash) + str.charAt(i); return (hash & 0x7FFFFFFF); /*/* End Of DJB Hash F

16、unction */ /*/* DEK算法*/ public static int DEKHash(String str) int hash = str.length(); for(int i = 0; i str.length(); i+) hash = (hash 27) str.charAt(i); return (hash & 0x7FFFFFFF); /*/* End Of DEK Hash Function */ /*/* AP算法*/ public static int APHash(String str) int hash = 0; for(int i = 0; i str.l

17、ength(); i+) hash = (i & 1) = 0) ? ( (hash 3) : (hash 5); / return (hash & 0x7FFFFFFF); return hash; /*/* End Of AP Hash Function */ /*/* JAVA自己带的算法*/ public static int java(String str) int h = 0; int off = 0; int len = str.length(); for (int i = 0; i len; i+) h = 31 * h + str.charAt(off+); return h; /*/* 混合hash算法，输出64位的值*/ public static long mixHash(String str) long hash = str.hashCode(); hash = 32; hash |= FNVHash1(str); return hash;