Build (method = -2) #dp: 678 Step-3' Graph: 55 vertices and 158 arcs (0.00s) Step-4' Graph: 6 vertices and 60 arcs (0.00s) #V4/#V3 = 0.11 #A4/#A3 = 0.38 Ready! (0.00s) Optimize a model with 24 rows, 61 columns and 175 nonzeros Presolve removed 3 rows and 3 columns Presolve time: 0.00s Presolved: 21 rows, 58 columns, 168 nonzeros Variable types: 0 continuous, 58 integer (0 binary) Found heuristic solution: objective 198.0000000 Found heuristic solution: objective 185.0000000 Optimize a model with 21 rows, 58 columns and 168 nonzeros Presolved: 21 rows, 58 columns, 168 nonzeros Root barrier log... Ordering time: 0.00s Barrier statistics: AA' NZ : 5.800e+01 Factor NZ : 2.310e+02 Factor Ops : 3.311e+03 (less than 1 second per iteration) Threads : 1 Objective Residual Iter Primal Dual Primal Dual Compl Time 0 6.28327273e+02 -8.88328197e+02 3.68e+01 1.11e-16 2.35e+01 0s 1 1.95068225e+02 -2.56202327e+02 9.49e-01 4.44e-16 3.70e+00 0s 2 9.22909615e+01 -6.75069784e+00 5.73e-02 3.33e-16 7.54e-01 0s 3 6.75098119e+01 6.13008951e+01 1.42e-14 2.78e-16 4.67e-02 0s 4 6.66946642e+01 6.63111961e+01 3.36e-14 1.13e-16 2.88e-03 0s 5 6.66666832e+01 6.66665914e+01 1.98e-14 2.22e-16 6.91e-07 0s 6 6.66666667e+01 6.66666666e+01 3.52e-14 2.22e-16 6.91e-10 0s Barrier solved model in 6 iterations and 0.00 seconds Optimal objective 6.66666667e+01 Root relaxation: objective 6.666667e+01, 45 iterations, 0.00 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time 0 0 66.66667 0 3 185.00000 66.66667 64.0% - 0s H 0 0 67.0000000 66.66667 0.50% - 0s Explored 0 nodes (57 simplex iterations) in 0.00 seconds Thread count was 1 (of 8 available processors) Optimal solution found (tolerance 0.00e+00) Best objective 6.700000000000e+01, best bound 6.700000000000e+01, gap 0.0% Preprocessing time: 0.01 seconds Gurobi run time: 0.00 seconds Total run time: 0.01 seconds Objective: 67 Solution: 14 x [1, 4, 8] 2 x [4, 13, 16] 1 x [3, 9, 10] 8 x [3, 14, 17] 13 x [7, 16, 18] 12 x [5, 10, 12] 3 x [5, 6, 14] 2 x [2, 7, 13] 7 x [8, 13, 15] 4 x [9, 14, 17] 1 x [11, 14]