// RS Hash Function
unsigned int
RSHash(
char
* str)
{
unsigned int
b = 378551 ;
unsigned int
a = 63689 ;
unsigned int
hash = 0 ;
while
(*str)
{
hash = hash * a + (*str ++ );
a *= b;
}
return
(hash & 0x7FFFFFFF );
}
// JS Hash Function
unsigned int
JSHash(
char
* str)
{
unsigned int
hash = 1315423911 ;
while
(*str)
{
hash ^= ((hash << 5 ) + (*str ++ ) + (hash >> 2 ));
}
return
(hash & 0x7FFFFFFF );
}
// P. J. Weinberger Hash Function
unsigned int
PJWHash(
char
* str)
{
unsigned int
BitsInUnignedInt = (
unsigned int
)( sizeof (
unsigned int
)*8 );
unsigned int
ThreeQuarters = (
unsigned int
)((BitsInUnignedInt*3 ) / 4 );
unsigned int
OneEighth = (
unsigned int
)(BitsInUnignedInt / 8 );
unsigned int
HighBits = (
unsigned int
)( 0xFFFFFFFF ) << (BitsInUnignedInt – OneEighth);
unsigned int
hash = 0 ;
unsigned int
test = 0 ;
while (*str)
{
hash = (hash << OneEighth) + (*str ++ );
if ((test = hash & HighBits) != 0 ) {
hash = ((hash ^ (test >> ThreeQuarters)) & ( ~ HighBits));
}
}
return (hash & 0x7FFFFFFF );
}
// ELF Hash Function
unsigned int
ELFHash(
char
* str)
{
unsigned int
hash = 0 ;
unsigned int
x = 0 ;
while (*str)
{
hash = (hash << 4 ) + (*str ++ );
if ((x = hash & 0xF0000000L ) != 0 ) {
hash ^= (x >> 24 );
hash &= ~ x;
}
}
return (hash & 0x7FFFFFFF );
}
// BKDR Hash Functionunsigned int
BKDRHash(
char
* str)
{
unsigned int
seed = 131 ; // 31 131 1313 13131 131313 etc..
unsigned int
hash = 0 ;
while (*str)
{
hash = hash*seed + (*str ++ );
}
return (hash & 0x7FFFFFFF );
}
// SDBM Hash Functionunsigned int
SDBMHash(
char
* str)
{
unsigned int
hash = 0 ;
while (*str)
{
hash = (*str ++ ) + (hash << 6 ) + (hash << 16 ) – hash;
}
return (hash & 0x7FFFFFFF );
}
// DJB Hash Functionunsigned int
DJBHash(
char
* str)
{
unsigned int
hash = 5381 ;
while (*str)
{
hash += (hash << 5 ) + (*str ++ );
}
return (hash & 0x7FFFFFFF );
}
// AP Hash Functionunsigned int
APHash(
char
* str)
{
unsigned int
hash = 0 ;
int i;
for (i = 0 ;*str; i ++ )
{
if ((i & 1 ) == 0 ) {
hash ^= ((hash << 7 ) ^ (*str ++ ) ^ (hash >> 3 ));
} else {
hash ^= ( ~ ((hash << 11 ) ^ (*str ++ ) ^ (hash >> 5 )));
}
}
return (hash & 0x7FFFFFFF );
}