Is this a linear programming problem?

*To*: mathgroup at smc.vnet.net*Subject*: [mg24961] Is this a linear programming problem?*From*: CDJ <cdjones+ at pitt.edu>*Date*: Mon, 28 Aug 2000 08:27:20 -0400 (EDT)*Organization*: University of Pittsburgh*Sender*: owner-wri-mathgroup at wolfram.com

Hello, I'm trying to solve the following problem, and I need a little bit of direction (I'd like to solve it on my own, so just some direction, please). Given: a 2 x n matrix whose entries are randomly selected from {0, 1, 2, 3, 4 , 5} Task: to "tidy up" the matrix in as few steps as possible Definition1: A _step_ is interchanging the locations of two elements in the matrix Definition2: To _tidy up_ a matrix is to re-arrange the elements so that all the 0's are together, all the 1's are together, etc. There are a few other specific constraints, but that's the general problem. Sort of like a disk defrag, or better yet, a 2d tower of hanoi puzzle. Is there any literature or anything on this? If possible, please email responses in addition to posting... thanks for any info, CDJ cdjones+ at pitt.edu