Build (method = -2) #dp: 2099 Step-3' Graph: 82 vertices and 236 arcs (0.01s) Step-4' Graph: 12 vertices and 96 arcs (0.01s) #V4/#V3 = 0.15 #A4/#A3 = 0.41 Ready! (0.01s) Optimize a model with 31 rows, 97 columns and 274 nonzeros Presolve removed 4 rows and 6 columns Presolve time: 0.00s Presolved: 27 rows, 91 columns, 262 nonzeros Variable types: 0 continuous, 91 integer (0 binary) Found heuristic solution: objective 199.0000000 Found heuristic solution: objective 114.0000000 Optimize a model with 27 rows, 91 columns and 262 nonzeros Presolved: 27 rows, 91 columns, 262 nonzeros Root barrier log... Ordering time: 0.00s Barrier statistics: AA' NZ : 9.900e+01 Factor NZ : 3.180e+02 Factor Ops : 5.010e+03 (less than 1 second per iteration) Threads : 1 Objective Residual Iter Primal Dual Primal Dual Compl Time 0 5.44844029e+02 -8.79373336e+02 1.10e+02 0.00e+00 1.96e+01 0s 1 1.46151160e+02 -3.39475014e+02 4.69e+00 3.33e-16 2.85e+00 0s 2 7.82454105e+01 6.21313631e+00 3.59e-03 4.44e-16 3.62e-01 0s 3 5.18683651e+01 3.47138281e+01 1.44e-04 1.94e-16 8.54e-02 0s 4 5.01333961e+01 4.94328034e+01 8.92e-15 3.33e-16 3.49e-03 0s 5 5.00002399e+01 4.99991873e+01 5.95e-15 2.22e-16 5.24e-06 0s 6 5.00000000e+01 5.00000000e+01 1.99e-14 3.33e-16 5.38e-12 0s Barrier solved model in 6 iterations and 0.00 seconds Optimal objective 5.00000000e+01 Root relaxation: objective 5.000000e+01, 76 iterations, 0.00 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time 0 0 50.00000 0 6 114.00000 50.00000 56.1% - 0s H 0 0 51.0000000 50.00000 1.96% - 0s H 0 0 50.0000000 50.00000 0.0% - 0s Explored 0 nodes (89 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 [4, 9, 17, 19] 9 x [1, 8, 13, 14] 4 x [1, 4, 11, 14] 1 x [1, 8, 15, 15] 3 x [1, 6, 17, 17] 3 x [3, 10, 14, 16] 4 x [3, 7, 9, 14] 7 x [4, 11, 12, 17] 1 x [5, 5, 17, 18] 1 x [3, 15, 16, 18] 15 x [2, 5, 6, 14]