Build (method = -2) #dp: 2868 Step-3' Graph: 80 vertices and 230 arcs (0.01s) Step-4' Graph: 8 vertices and 86 arcs (0.01s) #V4/#V3 = 0.10 #A4/#A3 = 0.37 Ready! (0.01s) Optimize a model with 27 rows, 87 columns and 252 nonzeros Presolve removed 3 rows and 4 columns Presolve time: 0.00s Presolved: 24 rows, 83 columns, 244 nonzeros Variable types: 0 continuous, 83 integer (0 binary) Found heuristic solution: objective 199.0000000 Found heuristic solution: objective 169.0000000 Optimize a model with 24 rows, 83 columns and 244 nonzeros Presolved: 24 rows, 83 columns, 244 nonzeros Root barrier log... Ordering time: 0.00s Barrier statistics: AA' NZ : 8.600e+01 Factor NZ : 3.000e+02 Factor Ops : 4.900e+03 (less than 1 second per iteration) Threads : 1 Objective Residual Iter Primal Dual Primal Dual Compl Time 0 5.38777174e+02 -9.08784540e+02 7.06e+01 1.11e-16 2.05e+01 0s 1 1.30064918e+02 -3.64779172e+02 1.42e-13 3.33e-16 2.78e+00 0s 2 7.75900888e+01 -3.16489600e+01 2.49e-14 2.22e-16 5.98e-01 0s 3 5.03243061e+01 4.20044602e+01 3.81e-13 5.20e-16 4.50e-02 0s 4 5.00107359e+01 4.99917605e+01 8.60e-14 4.62e-16 1.03e-04 0s 5 5.00000000e+01 5.00000000e+01 2.42e-14 5.10e-16 1.90e-10 0s Barrier solved model in 5 iterations and 0.00 seconds Optimal objective 5.00000000e+01 Root relaxation: objective 5.000000e+01, 72 iterations, 0.00 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time * 0 0 0 50.0000000 50.00000 0.0% - 0s Explored 0 nodes (72 simplex iterations) in 0.00 seconds Thread count was 1 (of 8 available processors) Optimal solution found (tolerance 0.00e+00) Best objective 5.000000000000e+01, best bound 5.000000000000e+01, gap 0.0% Preprocessing time: 0.02 seconds Gurobi run time: 0.00 seconds Total run time: 0.02 seconds Objective: 50 Solution: 2 x [5, 8, 9, 17] 10 x [1, 4, 5, 6] 1 x [1, 11, 14, 16] 7 x [2, 11, 16, 19] 14 x [3, 7, 12, 17] 3 x [9, 10, 10, 18] 4 x [3, 10, 14, 15] 6 x [8, 8, 10, 13] 3 x [2, 6, 8, 12]