Build (method = -2) #dp: 3056 Step-3' Graph: 84 vertices and 242 arcs (0.01s) Step-4' Graph: 8 vertices and 90 arcs (0.01s) #V4/#V3 = 0.10 #A4/#A3 = 0.37 Ready! (0.01s) Optimize a model with 28 rows, 91 columns and 264 nonzeros Presolve removed 3 rows and 4 columns Presolve time: 0.00s Presolved: 25 rows, 87 columns, 256 nonzeros Variable types: 0 continuous, 87 integer (8 binary) Found heuristic solution: objective 197.0000000 Found heuristic solution: objective 174.0000000 Optimize a model with 25 rows, 87 columns and 256 nonzeros Presolved: 25 rows, 87 columns, 256 nonzeros Root barrier log... Ordering time: 0.00s Barrier statistics: AA' NZ : 9.000e+01 Factor NZ : 3.250e+02 Factor Ops : 5.525e+03 (less than 1 second per iteration) Threads : 1 Objective Residual Iter Primal Dual Primal Dual Compl Time 0 8.31496305e+02 -9.13513684e+02 1.25e+02 2.79e-02 3.01e+01 0s 1 1.70991364e+02 -4.78279578e+02 4.46e+00 3.33e-16 4.06e+00 0s 2 9.23844279e+01 -1.18089623e+01 1.31e-02 2.22e-16 5.50e-01 0s 3 5.06700764e+01 4.15764461e+01 2.21e-04 3.33e-16 4.74e-02 0s 4 5.00177567e+01 4.99184183e+01 1.85e-07 2.14e-16 5.17e-04 0s 5 5.00000026e+01 4.99999906e+01 3.01e-13 2.22e-16 6.29e-08 0s 6 5.00000000e+01 5.00000000e+01 1.79e-14 2.22e-16 6.35e-14 0s Barrier solved model in 6 iterations and 0.00 seconds Optimal objective 5.00000000e+01 Root relaxation: objective 5.000000e+01, 75 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 (75 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: 6 x [2, 3, 13, 16] 2 x [2, 9, 15, 16] 1 x [1, 12, 13, 17] 9 x [8, 11, 13, 15] 13 x [7, 10, 18, 19] 1 x [3, 4, 16, 18] 1 x [3, 9, 12, 16] 4 x [1, 3, 3, 6] 11 x [4, 5, 12, 14] 1 x [5, 6, 19, 20] 1 x [5, 18, 19, 19]