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Article #35

a problem and a solution

#35
From: uwvaxgreg
Date: Thu, 06 May 1982 10:23
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In a corner of an APL News special edition for the APL81 Conference,
Jeff Shallit gives the following problems:  find two expressions,
each six characters or less, the first producing the vector 0 0 1 0 1,
and the second producing 0 1 0 0 1.  I am only able to come up with
solutions that work in origin zero.  Can anyone come up with solutions
that work in origin 1, or better, solutions that are origin-independent?
				- Greg Johnson
				  U Wis - Madison

By the way, the solution I had in mind for the problem of sorting the
rows of a matrix into lexicographic order involves decoding each row
into a scalar quantity, sorting those scalars, and then re-expanding
into a matrix.  This solution assumes an arbitrary-precision machine,
since for any large number L, a matrix containing the row
   1, ( ceiling 2 log L ) rho 0
when decoded will require that the machine be able to represent a number
larger than L.
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Path: arc1-ca.pugleaf.net!utzoo!decvax!harpo!uwvax!greg
From: uwvax!greg
Newsgroups: net.lang.apl
Subject: a problem and a solution
Date: Thu, 06 May 1982 10:23:22 +0000
Message-ID: <anews.Auwvax.357>