Build (method = -2) #dp: 24999 Step-3' Graph: 753 vertices and 16099 arcs (0.16s) Step-4' Graph: 745 vertices and 16083 arcs (0.17s) #V4/#V3 = 0.99 #A4/#A3 = 1.00 Ready! (0.17s) Optimize a model with 792 rows, 16084 columns and 46766 nonzeros Presolve removed 31 rows and 32 columns Presolve time: 0.54s Presolved: 761 rows, 16052 columns, 46830 nonzeros Variable types: 0 continuous, 16052 integer (13579 binary) Found heuristic solution: objective 26.0000000 Optimize a model with 761 rows, 16052 columns and 46830 nonzeros Presolved: 761 rows, 16052 columns, 46830 nonzeros Root barrier log... Ordering time: 0.02s Barrier statistics: AA' NZ : 3.216e+04 Factor NZ : 1.304e+05 (roughly 8 MBytes of memory) Factor Ops : 3.146e+07 (less than 1 second per iteration) Threads : 1 Objective Residual Iter Primal Dual Primal Dual Compl Time 0 4.14125570e+03 -3.58103839e+04 4.64e+04 1.52e-01 1.23e+01 0s 1 1.39718516e+03 -1.42230122e+04 7.27e+03 5.55e-16 2.14e+00 0s 2 3.98316683e+02 -7.47687182e+03 1.43e+03 5.00e-16 5.62e-01 0s 3 1.37020521e+02 -1.36552317e+03 1.92e+02 4.72e-16 9.17e-02 0s 4 5.61119329e+01 -1.78865342e+02 2.72e+01 5.55e-16 1.36e-02 0s 5 2.78110555e+01 -7.67676705e+01 9.78e+00 5.56e-16 5.32e-03 0s 6 1.47089114e+01 -3.99676408e+01 2.83e+00 4.85e-16 2.23e-03 0s 7 9.93953783e+00 -1.02856292e+01 1.02e+00 3.73e-16 7.52e-04 0s 8 7.97893351e+00 -1.99372972e+00 3.76e-01 2.45e-16 3.38e-04 0s 9 7.66133830e+00 -9.37296093e-02 2.29e-01 2.57e-16 2.55e-04 0s 10 7.47579812e+00 3.02699025e+00 1.82e-01 2.32e-16 1.45e-04 0s 11 7.14913256e+00 3.61987719e+00 7.14e-02 3.33e-16 1.12e-04 0s 12 7.02165833e+00 5.76678044e+00 2.65e-02 3.33e-16 3.95e-05 0s 13 6.95129852e+00 6.46368446e+00 1.01e-02 3.33e-16 1.53e-05 0s 14 6.91421827e+00 6.67741235e+00 4.00e-03 4.44e-16 7.41e-06 0s 15 6.89533221e+00 6.80339579e+00 1.71e-03 2.89e-16 2.88e-06 1s 16 6.88671346e+00 6.84290268e+00 9.57e-04 2.57e-16 1.37e-06 1s 17 6.87894468e+00 6.85900116e+00 3.11e-04 2.21e-16 6.23e-07 1s 18 6.87507210e+00 6.87426653e+00 1.10e-14 3.04e-16 2.51e-08 1s 19 6.87500022e+00 6.87499860e+00 1.40e-14 3.54e-16 5.06e-11 1s 20 6.87500000e+00 6.87500000e+00 3.04e-14 5.28e-16 5.20e-17 1s Barrier solved model in 20 iterations and 0.64 seconds Optimal objective 6.87500000e+00 Root relaxation: objective 6.875000e+00, 12425 iterations, 1.08 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time 0 0 6.87500 0 74 26.00000 6.87500 73.6% - 3s H 0 0 9.0000000 6.87500 23.6% - 3s H 0 0 8.0000000 6.87500 14.1% - 3s 0 0 6.87500 0 122 8.00000 6.87500 14.1% - 5s H 0 0 7.0000000 6.87500 1.79% - 5s Cutting planes: Gomory: 1 Zero half: 4 Explored 0 nodes (20624 simplex iterations) in 5.22 seconds Thread count was 1 (of 8 available processors) Optimal solution found (tolerance 0.00e+00) Best objective 7.000000000000e+00, best bound 7.000000000000e+00, gap 0.0% Preprocessing time: 0.23 seconds Gurobi run time: 5.22 seconds Total run time: 5.45 seconds Objective: 7 Solution: 1 x [4, 13, 19, 22, 33, 42, 43] 1 x [2, 6, 7, 9, 10, 28, 34, 37] 1 x [12, 14, 25, 32, 41, 46] 1 x [1, 5, 17, 27, 29, 45, 47] 1 x [3, 18, 20, 21, 26, 30, 35] 1 x [2, 15, 23, 24, 29, 44] 1 x [8, 11, 12, 16, 31, 36, 38, 39, 40]