Build (method = -2) #dp: 8834 Step-3' Graph: 115 vertices and 334 arcs (0.04s) Step-4' Graph: 20 vertices and 144 arcs (0.04s) #V4/#V3 = 0.17 #A4/#A3 = 0.43 Ready! (0.04s) Optimize a model with 40 rows, 145 columns and 403 nonzeros Presolve removed 6 rows and 10 columns Presolve time: 0.00s Presolved: 34 rows, 135 columns, 384 nonzeros Variable types: 0 continuous, 135 integer (0 binary) Found heuristic solution: objective 199.0000000 Found heuristic solution: objective 138.0000000 Optimize a model with 34 rows, 135 columns and 384 nonzeros Presolved: 34 rows, 135 columns, 384 nonzeros Root barrier log... Ordering time: 0.00s Barrier statistics: AA' NZ : 1.520e+02 Factor NZ : 3.730e+02 Factor Ops : 5.445e+03 (less than 1 second per iteration) Threads : 1 Objective Residual Iter Primal Dual Primal Dual Compl Time 0 6.03864734e+02 -1.20283458e+03 2.56e+02 1.11e-16 2.00e+01 0s 1 1.35976685e+02 -5.32152681e+02 3.67e+00 6.66e-16 2.54e+00 0s 2 8.52460854e+01 -8.57697124e+01 3.65e-02 2.94e-15 6.01e-01 0s 3 4.43462908e+01 1.78981324e+01 1.30e-04 3.33e-16 9.13e-02 0s 4 4.04482986e+01 3.88688713e+01 1.31e-05 3.07e-16 5.45e-03 0s 5 4.00012368e+01 3.99900659e+01 3.55e-09 2.22e-16 3.85e-05 0s 6 4.00000000e+01 4.00000000e+01 2.96e-14 2.22e-16 1.53e-10 0s Barrier solved model in 6 iterations and 0.00 seconds Optimal objective 4.00000000e+01 Root relaxation: objective 4.000000e+01, 112 iterations, 0.00 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time * 0 0 0 40.0000000 40.00000 0.0% - 0s Explored 0 nodes (112 simplex iterations) in 0.00 seconds Thread count was 1 (of 8 available processors) Optimal solution found (tolerance 0.00e+00) Best objective 4.000000000000e+01, best bound 4.000000000000e+01, gap 0.0% Preprocessing time: 0.05 seconds Gurobi run time: 0.00 seconds Total run time: 0.05 seconds Objective: 40 Solution: 13 x [2, 4, 6, 8, 12] 2 x [1, 7, 13, 15, 18] 1 x [3, 11, 13, 15, 19] 6 x [10, 14, 15, 15, 16] 12 x [1, 9, 13, 17, 20] 4 x [2, 3, 5, 9, 11] 1 x [2, 3, 9, 12, 16] 1 x [2, 7, 13, 13, 19]