Tim Daly, Jr. <tim@tenkan.org> wrote:
+---------------
| "Paul F. Dietz" <dietz@dls.net> writes:
| > (idea: detect circularity using the standard two pointer trick
| > and use MOD to reduce n to a manageable size.)
| 
| Could someone please clue me in on the "standard two pointer trick"?
+---------------

Do a web search for:

	tortoise hare circular

or perhaps better:

	tortoise hare "circular list"

Also see CLHS "Function LIST-LENGTH". As shown there, a common approach
is to have the hare move at twice the speed of the tortoise, but many
other winning strategies are possible [iff your termination tests are
correct!]. E.g., make the tortoise move at half the speed of the hare.
[It is useful to ask why/how this might be different than the previous,
and whether or not one might be "better" than the other in some sense.]


-Rob

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Rob Warnock, PP-ASEL-IA		<rpw3@rpw3.org>
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