There's been a lot of work done on these over the years, but in fact, it's pretty hard to invent a good hash function. So my advice to you is, if you want to use something was a hash, go to a library. Look up a good hash function.

已经做过了很多的尝试和努力,但是事实是，很难发明出一个好的哈希函数,所以我给你们的建议是,如果你们想使用哈希功能,到函数库中查找一个好的哈希函数。

麻省理工公开课 - 计算机科学及编程导论课程节选

So let's look at the second example, all right, I keep doing that -- this piece of code from here to here gives me a way of now creating a hash table of size 256.

所以让我们来看一下第二个例子，好的，我继续做那件事,这段代码中从这里到这里,是创建一个大小为256的哈希表。

麻省理工公开课 - 计算机科学及编程导论课程节选

That in many cases, I can gain efficiency if I'm willing to give up space. Having said that though, there may still be a problem, or there ought to be a problem that may be bugging you slightly, which is how do I guarantee that my hash function takes any input into exactly one spot in the storage space?

普遍存在的增益和权衡,在许多的例子中,可以通过牺牲空间而得到效率方面的增加,话说回来，仍然存在一个问题,或者应该会有一个问题困扰着你,就是我如何保证我的哈希函数能够准确将,任一输入映射到相应的唯一的存贮空间中去？

麻省理工公开课 - 计算机科学及编程导论课程节选