Build (method = -2) #dp: 3028 Step-3' Graph: 84 vertices and 242 arcs (0.01s) Step-4' Graph: 12 vertices and 98 arcs (0.01s) #V4/#V3 = 0.14 #A4/#A3 = 0.40 Ready! (0.01s) Optimize a model with 31 rows, 99 columns and 280 nonzeros Presolve removed 4 rows and 6 columns Presolve time: 0.00s Presolved: 27 rows, 93 columns, 268 nonzeros Variable types: 0 continuous, 93 integer (0 binary) Found heuristic solution: objective 199.0000000 Found heuristic solution: objective 138.0000000 Optimize a model with 27 rows, 93 columns and 268 nonzeros Presolved: 27 rows, 93 columns, 268 nonzeros Root barrier log... Ordering time: 0.00s Barrier statistics: AA' NZ : 1.000e+02 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 5.31889406e+02 -8.80348204e+02 1.23e+02 1.11e-16 1.89e+01 0s 1 1.34208093e+02 -3.40724387e+02 2.01e+00 3.33e-16 2.53e+00 0s 2 8.58627125e+01 -6.64727066e+01 2.26e-01 8.33e-16 7.59e-01 0s 3 5.24242930e+01 3.94727574e+01 1.02e-03 1.53e-16 6.32e-02 0s 4 5.02096480e+01 4.94898817e+01 4.20e-05 1.45e-16 3.51e-03 0s 5 5.00001546e+01 4.99992370e+01 4.58e-09 3.33e-16 4.48e-06 0s 6 5.00000000e+01 5.00000000e+01 1.73e-14 2.23e-16 4.49e-12 0s Barrier solved model in 6 iterations and 0.00 seconds Optimal objective 5.00000000e+01 Root relaxation: objective 5.000000e+01, 78 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 (78 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: 1 x [4, 14, 16, 17] 3 x [2, 4, 5, 6] 2 x [6, 11, 17, 18] 1 x [7, 13, 17, 18] 7 x [7, 13, 15, 17] 8 x [3, 9, 16, 17] 5 x [7, 8, 11, 12] 2 x [1, 7, 8, 19] 5 x [7, 8, 9, 10] 16 x [2, 13, 14, 19]