Article View: comp.theory
Article #1972Help with an NP-complete problem
From: STYLIADH
Date: Thu, 14 Dec 1989 21:59
Date: Thu, 14 Dec 1989 21:59
38 lines
1392 bytes
1392 bytes
I am dealing with the following NP_complete
Let A be a three dimensional matrix A[1..n][1..m][1..w], of INTEGERS,
xn[1..n] a one dimensional matrix of INTEGERS and N[1..n] a one dimensional
matrix of integers in the range 1..n.
Given the sums
n
(A) SUM A[i][j][k] foreach j in [1,m] ,k in [1,w].
i=1
m
(B) SUM A[i][j][k] foreach i in [1,n],k in [1,w].
j=1
w
(C) SUM A[i][j][k] foreach i in [1,n],j in [1,m]
k=1
and the fact that :
from the n elements A[i][j][k], j in [1,m],k in [1,w],N[i] of them have a
known integer value xn[i] and n-N[i] of them have the value xn[i]+1.
xn[i]>=0 foreach i.
A[i][j][k] >=0 foreach i,j,k.
which are the elements A[i][j][k] foreach i in [1,n],j in [1,m],k in [1,w]?
The problem obviously is NP-complete.
I wonder if anyone can help me with aproximation methods or clever heuristics
or anything.
I would welcome any coments,bibliography,ideas anything.
Many thanks.
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Path: arc1-ca.pugleaf.net!utzoo!attcan!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!cs.utexas.edu!tut.cis.ohio-state.edu!ucbvax!GRPATVX1.BITNET!STYLIADH From: STYLIADH@GRPATVX1.BITNET Newsgroups: comp.theory Subject: Help with an NP-complete problem Message-ID: <C-247.THEORYNT@ibm.com> Date: 14 Dec 89 21:59:41 GMT Sender: daemon@ucbvax.BERKELEY.EDU Reply-To: STYLIADH%GRPATVX1.BITNET@VM1.NoDak.EDU Lines: 38