steiner covering problems

examples/data/scp/README.steiner_triple.txt

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+STEINER TRIPLE COVERING PROBLEM test instances
+
+Let n = number of variables
+    m = number of triples
+    T(i) = set of 3 indices of i-th triple
+
+The problem is;
+
+MIN \sum_{j=1]^n x_j
+
+SUBJ. TO:
+
+\sum_{j \in T(i)} x_j \geq 1, for i = 1,...,m,
+
+x_j \in {0,1} for all j = 1,...,n
+
+
+
+
+The following files are in the distribution:
+
+FILE       : INSTANCE  :    n   :     m
+............................................
+data.9     : stn9      :    9   :    12
+data.15    : stn15     :   15   :    35   
+data.27    : stn27     :   27   :   117   
+data.45    : stn45     :   45   :   330   
+data.81    : stn81     :   81   :  1080   
+data.135   : stn135    :  135   :  3015   
+data.243   : stn243    :  243   :  9801   
+data.405   : stn405    :  405   : 27270   
+data.729   : stn729    :  729   : 88452   
+
+The file format is:
+
+Line 1: n m
+Lines 2 to m+1:  3 variable indices for triple
+
+
+Best known solutions 
+
+stn9      :   5  optimal (Fulkerson et al., 1974)
+stn15     :   9  optimal (Fulkerson et al., 1974)
+stn27     :  18  optimal (Fulkerson et al., 1974)
+stn45     :  30  optimal (Ratliff, 1979)
+stn81     :  61  optimal (Mannino and Sassano, 1995)
+stn135    : 103  optimal (Ostrowski et al., 2009, 2010)
+stn243    : 198  optimal (Ostrowski et al., 2009, 2010)
+stn405    : 335  BKS     (Resende & Toso, 2010)
+stn729    : 617  BKS     (Resende & Toso, 2010)
+