RS哈希程序

时间:2011-05-26 10:16:23

标签: algorithm hash

有人可以告诉我RS字符串哈希算法的工作原理或算法吗?我需要它,但在谷歌上找不到。请至少帮我解决这个算法,我会自己实现它。

3 个答案:

答案 0 :(得分:7)

您的意思是Robert Sedgewick的字符串哈希算法吗?

uint a = 63689, uint b = 378551
foreach ( byte x ; bytes ) {
    value = value * a + x;
    a *= b;
}
return value;

(引自http://pallas.telperion.info/d/hash/)。

答案 1 :(得分:0)

Python实现如下:

def RSHash(key):
    a = 63689
    b = 378551
    hash = 0
    for i in range(len(key)):
        hash = hash * a + ord(key[i])
        a = a * b
return hash

答案 2 :(得分:0)

C ++实现如下:

unsigned int RSHash(const std::string& str)
{
   unsigned int b    = 378551;
   unsigned int a    = 63689;
   unsigned int hash = 0;

   for(std::size_t i = 0; i < str.length(); i++)
   {
      hash = hash * a + str[i];
      a    = a * b;
   }

   return hash;
}
/* End Of RS Hash Function */