/**
* Thomas Wang的算法整数hash
*/
public static int intHash(int key)
{
key += ~(key << );
key ^= (key >>> );
key += (key << );
key ^= (key >>> );
key += ~(key << );
key ^= (key >>> );
return key;
}
/**
* RS算法hash
* @param str 字符串
*/
public static int RSHash(String str)
{
int b = ;
int a = ;
int hash = ;
for(int i = ; i < strlength(); i++)
{
hash = hash * a + strcharAt(i);
a = a * b;
}
return (hash & xFFFFFFF);
}
/* End Of RS Hash Function */
/**
* JS算法
*/
public static int JSHash(String str)
{
int hash = ;
for(int i = ; i < strlength(); i++)
{
hash ^= ((hash << ) + strcharAt(i) + (hash >> ));
}
return (hash & xFFFFFFF);
}
/* End Of JS Hash Function */
/**
* PJW算法
*/
public static int PJWHash(String str)
{
int BitsInUnsignedInt = ;
int ThreeQuarters = (BitsInUnsignedInt * ) / ;
int OneEighth = BitsInUnsignedInt / ;
int HighBits = xFFFFFFFF << (BitsInUnsignedInt OneEighth);
int hash = ;
int test = ;
for(int i = ; i < strlength();i++)
{
hash = (hash << OneEighth) + strcharAt(i);
if((test = hash & HighBits) != )
{
hash = (( hash ^ (test >> ThreeQuarters)) & (~HighBits));
}
}
return (hash & xFFFFFFF);
}
/* End Of P J Weinberger Hash Function */
/**
* ELF算法
*/
public static int ELFHash(String str)
{
int hash = ;
int x = ;
for(int i = ; i < strlength(); i++)
{
hash = (hash << ) + strcharAt(i);
if((x = (int)(hash & xFL)) != )
{
hash ^= (x >> );
hash &= ~x;
}
}
return (hash & xFFFFFFF);
}
/* End Of ELF Hash Function */
/**
* BKDR算法
*/
public static int BKDRHash(String str)
{
int seed = ; // etc
int hash = ;
for(int i = ; i < strlength(); i++)
{
hash = (hash * seed) + strcharAt(i);
}
return (hash & xFFFFFFF);
}
/* End Of BKDR Hash Function */
/**
* SDBM算法
*/
public static int SDBMHash(String str)
{
int hash = ;
for(int i = ; i < strlength(); i++)
{
hash = strcharAt(i) + (hash << ) + (hash << ) hash;
}
return (hash & xFFFFFFF);
}
/* End Of SDBM Hash Function */
/**
* DJB算法
*/
public static int DJBHash(String str)
{
int hash = ;
for(int i = ; i < strlength(); i++)
{
hash = ((hash << ) + hash) + strcharAt(i);
}
return (hash & xFFFFFFF);
}
/* End Of DJB Hash Function */
/**
* DEK算法
*/
public static int DEKHash(String str)
{
int hash = strlength();
for(int i = ; i < strlength(); i++)
{
hash = ((hash << ) ^ (hash >> )) ^ strcharAt(i);
}
return (hash & xFFFFFFF);
}
/* End Of DEK Hash Function */
/**
* AP算法
*/
public static int APHash(String str)
{
int hash = ;
for(int i = ; i < strlength(); i++)
{
hash ^= ((i & ) == ) ? ( (hash << ) ^ strcharAt(i) ^ (hash >> )) :
(~((hash << ) ^ strcharAt(i) ^ (hash >> )));
}
// return (hash & xFFFFFFF);
return hash;
}
/* End Of AP Hash Function */
/**
* JAVA自己带的算法
*/
public static int java(String str)
{
int h = ;
int off = ;
int len = strlength();
for (int i = ; i < len; i++)
{
h = * h + strcharAt(off++);
}
return h;
}
/**
* 混合hash算法输出位的值
*/
public static long mixHash(String str)
{
long hash = strhashCode();
hash <<= ;
hash |= FNVHash(str);
return hash;
}
}
