字符串hash函数

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著名的字符串hash函数--elfhash:

Pascal代码:

 function ELFhash(x:string):longint;
var
     i,h,g:longint;
begin
         h:=0;
         for i:=1 to length(x) do
         begin
                  h:=(h shl 4)+ord(x[i]);
                 g:=h and $f0000000;
                  if g<>0 then h:=h xor (g shr 24);
                  h:=h and (not g);
        end;
        exit(h mod Max);
end;

C代码:

int hasher(char *k)

{
 unsigned long h=0,g;
 while(*k){
  h=(h<<4)+*k++;
  g=h &0xf0000000l; //7个0;
  if(g) h^=g>>24;
  h&=~g;
 }
 return h;
}

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