The library contains instances for the p-Median (PMP) and 
Simple Plant Location (SPLP) problems that are supposed to be 
hard from the point of view of possibility of problem size reduction
without any algorithms for solving it to optimality. 
We expect that these instances might be difficult for finding an exact 
(not approximating solutions) optimal solution.
Each instance contains a square cost matrix and a vector of 
fixed costs (for SPLP).
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Data format
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Instances are stored in text files named XmatrY,Z.txt, where
X = 't' if permutation is deterministic Pij=(i+j) mod n
  = 'r' if permutation is randomized
Y = m = n - size of the costs matrix
Z - upper bound on differences, i.e differences between two successive 
    sorted elements in each column are drawn uniformly at random from [1,Z].
The first line in the output file contains two decimal numbers, m and n.
Next, the costs matrix is given row by row.
After the costs matrix the vector of fixed opening costs is given in the
same manner: a line with dimensions (m and 1) followed by a line with
elements of the vector.
All numbers within one line are delimited by tabulations ('\t' in C/C++ notation).