djb hash

Primary objective: to find a hash function that supports 64-bit integer computation efficiently, so that the efficiency in speed and space is higher than that of other function functions, and 32-bit integer computation in internal

Found the original of this seriesHttp://www.cnblogs.com/rush/archive/2012/02/05/2339037.htmlRecently, network security has become a focal point, in addition to the security events of plaintext passwords in China, there is one more thing that affects

Some of the most critical aspects of a hash table are: Access via key (calculates key by hash function) Mapped to data structures (the storage structure of the hash table itself) Processing of mappings (conflict or collision

Basic ConceptsThe so-called perfect hash function refers to a hash function without conflict, that is, to any key1! = Key2 has h (key1 )! = H (key2 ).Set the custom domain to X, the value range to Y, n = | X |, m = | Y |, then there must be m> = n.

function Djbhash ($STR)//0.22 { $hash = 0; $n = strlen ($STR); for ($i = 0; $i { $hash + = ($hash } return $hash% 701819; } function Elfhash ($STR)//0.35 { $hash = $x = 0; $n =

/***************************************** ************************************* General Purpose hash function algorithms library **** Author: Arash partow-2002 ** URL: http://www.partow.net ** URL:

Yesterday learned the use of hash table, and did some problems, to the hash more understanding. Let's do the hash algorithm today so that the puzzle can be done ... This is reproduced by others, because the essence of the hash is to determine the

Yesterday learned the use of the hash table, and did some problems, the hash more understanding. Today, let's do the hashing algorithm so that the puzzle can be done ... This is reproduced others, because the essence of the hash is to determine the

Common hash Functions The generic hash function library has the following string hashing algorithms that mix addition and one operation. The following algorithms are different in terms of usage and functionality, but can be used as an example to

http://blog.csdn.net/kingstar158/article/details/8028635Because of the work needs, for tens other data, the use of stl::map there is really a problem of efficiency, and finally use Boost::unordered_map replace the former, found that there is a great