> llong pollard(llong n)
> {//返回 n 的一个质因子 
>     srand(rand()+n);
>     llong i,k,d,c,x,y;
>     i = 1;     k = 2;
>     y = x = abs(rand()%(n-1))+1;
>     c = abs(rand()%(n-1))+1;
>     do
>     {
>         i++;
>         d = GCD(n+y-x,n);
>         if(d>1&&d<n)
>             return d;
>         if(i==k)
>         {
>             y = x; 
>             k *= 2;
>          }
>  //        x = ((x%n)*x)%n - c + n;
>          x = mul_mod(x,x,n) - c + n;
>   //       c = abs(rand()%(n-1))+1;
>     }while(y!=x);
>     return n;
> } 

• 换新服务器了？同样的code，以前 800ms，现在 400ms (0) sunmoonstar_love 2005-08-17 23:36:59