Build (method = -2) #dp: 3809 Step-3' Graph: 149 vertices and 440 arcs (0.02s) Step-4' Graph: 22 vertices and 186 arcs (0.02s) #V4/#V3 = 0.15 #A4/#A3 = 0.42 Ready! (0.02s) Optimize a model with 57 rows, 187 columns and 521 nonzeros Presolve removed 6 rows and 9 columns Presolve time: 0.00s Presolved: 51 rows, 178 columns, 499 nonzeros Variable types: 0 continuous, 178 integer (88 binary) Found heuristic solution: objective 18.0000000 Optimize a model with 51 rows, 178 columns and 499 nonzeros Presolved: 51 rows, 178 columns, 499 nonzeros Root barrier log... Ordering time: 0.00s Barrier statistics: AA' NZ : 2.000e+02 Factor NZ : 6.440e+02 Factor Ops : 1.216e+04 (less than 1 second per iteration) Threads : 1 Objective Residual Iter Primal Dual Primal Dual Compl Time 0 2.30712400e+02 -3.49745915e+02 6.68e+01 5.40e-02 4.08e+00 0s 1 3.81360983e+01 -1.18352471e+02 2.34e-01 6.66e-16 4.50e-01 0s 2 2.10293878e+01 -9.71871712e+00 1.77e-03 2.02e-02 8.60e-02 0s 3 1.27660263e+01 9.09469823e+00 1.01e-04 4.86e-16 1.01e-02 0s 4 1.25021530e+01 1.24914236e+01 5.22e-14 6.66e-16 2.94e-05 0s 5 1.25000000e+01 1.25000000e+01 1.02e-14 4.20e-16 3.51e-11 0s Barrier solved model in 5 iterations and 0.00 seconds Optimal objective 1.25000000e+01 Root relaxation: objective 1.250000e+01, 125 iterations, 0.00 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time 0 0 12.50000 0 4 18.00000 12.50000 30.6% - 0s H 0 0 13.0000000 12.50000 3.85% - 0s Explored 0 nodes (157 simplex iterations) in 0.01 seconds Thread count was 1 (of 8 available processors) Optimal solution found (tolerance 0.00e+00) Best objective 1.300000000000e+01, best bound 1.300000000000e+01, gap 0.0% Preprocessing time: 0.04 seconds Gurobi run time: 0.01 seconds Total run time: 0.04 seconds Objective: 13 Solution: 1 x [17, 23, 33, 35] 1 x [18, 24, 30, 34] 1 x [17, 23, 28, 32] 2 x [12, 19, 30, 31] 1 x [16, 16, 25, 30] 1 x [12, 15, 21, 29] 1 x [12, 15, 27] 1 x [2, 2, 2, 26] 1 x [11, 13, 22] 1 x [5, 8, 10, 20] 1 x [1, 4, 9, 18] 1 x [3, 6, 7, 14]