Build (method = -2) #dp: 7296 Step-3' Graph: 1059 vertices and 3170 arcs (0.05s) Step-4' Graph: 728 vertices and 2508 arcs (0.05s) #V4/#V3 = 0.69 #A4/#A3 = 0.79 Ready! (0.05s) Optimize a model with 747 rows, 2509 columns and 6075 nonzeros Presolve removed 156 rows and 305 columns Presolve time: 0.05s Presolved: 591 rows, 2204 columns, 5897 nonzeros Variable types: 0 continuous, 2204 integer (359 binary) Found heuristic solution: objective 72.0000000 Optimize a model with 591 rows, 2204 columns and 5897 nonzeros Presolved: 591 rows, 2204 columns, 5897 nonzeros Root barrier log... Ordering time: 0.00s Barrier statistics: AA' NZ : 4.071e+03 Factor NZ : 2.289e+04 (roughly 1 MByte of memory) Factor Ops : 1.478e+06 (less than 1 second per iteration) Threads : 1 Objective Residual Iter Primal Dual Primal Dual Compl Time 0 1.13502948e+03 -3.12275711e+04 7.51e+04 2.26e-02 1.01e+02 0s 1 2.86273964e+02 -2.10391355e+04 8.82e+03 7.77e-16 1.51e+01 0s 2 1.41212947e+02 -8.02256342e+03 1.51e+03 2.66e-15 3.32e+00 0s 3 9.84884343e+01 -1.60034351e+03 2.81e+02 2.22e-15 6.23e-01 0s 4 7.33146008e+01 -6.98645755e+02 9.56e+01 8.60e-16 2.45e-01 0s 5 6.21468263e+01 -3.09444732e+02 4.22e+01 1.25e-15 1.09e-01 0s 6 5.40977873e+01 -2.36489143e+02 1.57e+01 1.10e-15 7.42e-02 0s 7 4.53461044e+01 -1.21330034e+02 4.40e+00 1.17e-15 3.95e-02 0s 8 3.80566176e+01 -9.77730736e+01 3.01e+00 1.43e-15 3.19e-02 0s 9 3.25963496e+01 -2.30747747e+01 1.06e+00 1.04e-15 1.29e-02 0s 10 2.98066362e+01 -3.26893821e+00 5.73e-01 1.14e-15 7.63e-03 0s 11 2.87354297e+01 1.26700119e+01 2.84e-01 1.21e-15 3.70e-03 0s 12 2.80384815e+01 2.72288430e+01 1.25e-02 8.42e-16 1.86e-04 0s 13 2.80000515e+01 2.79992287e+01 2.86e-13 9.29e-16 1.86e-07 0s 14 2.80000001e+01 2.79999992e+01 5.86e-14 8.70e-16 1.86e-10 0s 15 2.80000000e+01 2.80000000e+01 1.36e-13 8.88e-16 1.86e-13 0s Barrier solved model in 15 iterations and 0.05 seconds Optimal objective 2.80000000e+01 Root relaxation: objective 2.800000e+01, 1184 iterations, 0.07 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time * 0 0 0 28.0000000 28.00000 0.0% - 0s Explored 0 nodes (1184 simplex iterations) in 0.16 seconds Thread count was 1 (of 8 available processors) Optimal solution found (tolerance 0.00e+00) Best objective 2.800000000000e+01, best bound 2.800000000000e+01, gap 0.0% Preprocessing time: 0.07 seconds Gurobi run time: 0.16 seconds Total run time: 0.23 seconds Objective: 28 Solution: 2 x [1, 2, 3, 7, 11, 14] 1 x [1, 2, 11, 13, 15, 18, 19] 1 x [1, 2, 11, 13, 19] 3 x [1, 3, 4, 10, 11, 13, 15] 1 x [1, 3, 5, 6, 11, 14, 15, 17, 19] 2 x [1, 3, 5, 6, 11, 14, 15, 18] 2 x [1, 5, 6, 7, 9, 11, 15] 2 x [1, 5, 6, 11, 14, 18] 1 x [1, 5, 6, 11, 14, 19] 2 x [1, 9, 11, 12, 13, 14, 16, 18] 3 x [2, 3, 7, 10, 11, 13, 14, 18] 2 x [3, 5, 6, 7, 11, 13, 15, 18] 2 x [3, 9, 10, 11, 13, 14, 18] 1 x [4, 6, 7, 11, 12, 13, 14, 15, 18] 2 x [6, 7, 11, 12, 13, 14, 15, 18] 1 x [7, 8, 11]