NetNews Usenet Archive 1993 #1/NN_1993_1.iso/spool/comp/lang/c/19344

Text File | 1993-01-06 | 1.8 KB | 41 lines

Newsgroups: comp.lang.c
Path: sparky!uunet!mnemosyne.cs.du.edu!nyx!jepler
From: [e-mail] (Jeff Epler)
Subject: Sparse 4+dimentional array?
Message-ID: <[e-mail]>
Sender: [e-mail] (netnews admin account)
Organization: Nyx, Public Access Unix @ U. of Denver Math/CS dept.
Date: Thu, 7 Jan 93 01:26:16 GMT
Lines: 30

I recently created a program that creates "words" based on letter
probabilities found in text files fed to it.  It uses a table which
relates the last two letters in the word to the probability of the next
letter. (IE maybe "o" follows "zo" 95% of the time, but "n" does 5%).
I now have the desire to allow the program to use a table of more than
the past two letters.

However, my compiler (No, this is *not* an implementation specific query,
really) and OS restrict me to 640K, with no array bigger than 64K (Can you
guess what OS this is? You're right.)  -- This means that declaring such
a large array as
 int table[27][27][27][28]
is *not* an option.. (this is some 500K), and more levels are also "out
of the question."  However, many letter combinations will never be used
 -- ZZZ? or QAA? or QWE? -- So I concieved of the idea of using a sparse
array.

So, since I have seen (Though more often in comp.lang.pascal) posts
which detail how to create and manipulate sparse matricies, I hope
someone here can help me.. (All of the posts, which are probably
expired, have only spoken about two-dimensional sparse matricies, though.)

Code would be nice, (Some sparse-matrix C program even) but ideas or
algorithm pointers would do fine.. Thanks.. (Feel free to mail or
post -- I try to keep up in here..)

--
Jeff Epler [e-mail] or [e-mail] (preferred)

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