Re: hash two keys to one index
Mark wrote:
Ahh.. yes. I was getting my terminology mixed up. Ive been using
"hash" to mean the value that is returned by the hash function, and
"key" to mean the array index (after applying hocus pocus to the hash).
Eric Sosman wrote:
You compare the bucket's key to
the search key to find out whether this is the desired pair or
whether you need to probe further.
I was thinking about passing a reference to the object into the "find"
method and then comparing the two objects... but of couse, this really
doesn't make sense. If you already know what the object is, you don't
need to search for it. [...]
No, but you might want to ask a different kind of question,
like "Is this Student enrolled in Basket Weaving 101?" Given a
Student and a collection of all the enrollees in BW101, the
problem isn't so much to find the Student as to determine whether
he is or isn't in the collection. That's why Java has HashSet
(and other Set flavors, too).
> [in re Knuth:]
> I'm not really a textbook sort of guy (more hands on), but I'll keep
> this is mind.
As in many other endeavors, hands-on will suffice for a while
and take you for a certain distance. But eventually you will find
that progress depends on being able to gain from the experience of
others without expending all the time they did while acquiring it.
(Unless you happen to be immortal with a lot of time on your hands,
or such a blazing genius that you can re-invent an entire field of
knowledge overnight and without aid.) To paraphrase a fairly smart
person, it is foolish to turn down a giant's offer to allow you to
stand on his shoulder.
--
Eric Sosman
esosman@acm-dot-org.invalid