Build (method = -2) #dp: 49653 Step-3' Graph: 723 vertices and 7216 arcs (0.37s) Step-4' Graph: 593 vertices and 6958 arcs (0.37s) #V4/#V3 = 0.82 #A4/#A3 = 0.96 Ready! (0.37s) Optimize a model with 638 rows, 6959 columns and 19693 nonzeros Presolve removed 48 rows and 50 columns Presolve time: 0.15s Presolved: 590 rows, 6909 columns, 19802 nonzeros Variable types: 0 continuous, 6909 integer (4968 binary) Found heuristic solution: objective 37.0000000 Optimize a model with 590 rows, 6909 columns and 19802 nonzeros Presolve removed 2 rows and 2 columns Presolved: 588 rows, 6907 columns, 19802 nonzeros Root barrier log... Ordering time: 0.01s Barrier statistics: AA' NZ : 1.334e+04 Factor NZ : 4.463e+04 (roughly 3 MBytes of memory) Factor Ops : 4.470e+06 (less than 1 second per iteration) Threads : 1 Objective Residual Iter Primal Dual Primal Dual Compl Time 0 4.31560968e+03 -3.30442858e+04 4.65e+04 1.81e-01 2.56e+01 0s 1 1.13263351e+03 -1.05108906e+04 1.13e+04 6.66e-16 6.19e+00 0s 2 2.34920157e+02 -4.37518611e+03 1.59e+03 6.66e-16 1.04e+00 0s 3 1.00363357e+02 -1.47658223e+03 2.73e+02 6.66e-16 2.28e-01 0s 4 5.50022028e+01 -3.88493262e+02 6.39e+01 6.31e-16 5.65e-02 0s 5 3.03582019e+01 -1.65313709e+02 1.99e+01 6.59e-16 2.12e-02 0s 6 2.08435457e+01 -6.80331578e+01 8.80e+00 5.96e-16 9.11e-03 0s 7 1.50758525e+01 -3.64268423e+01 5.03e+00 6.66e-16 5.07e-03 0s 8 1.30146449e+01 -2.84502444e+01 4.01e+00 6.56e-16 4.00e-03 0s 9 8.84882877e+00 -1.12105225e+01 1.30e+00 5.32e-16 1.69e-03 0s 10 7.71066980e+00 -9.43192022e-01 6.26e-01 3.33e-16 7.00e-04 0s 11 7.63783751e+00 1.48550784e+00 4.60e-01 3.69e-16 4.87e-04 0s 12 7.46204649e+00 3.13397084e+00 2.54e-01 6.19e-16 3.32e-04 0s 13 7.23460298e+00 6.67795304e+00 4.81e-03 3.59e-16 4.04e-05 0s 14 7.14395805e+00 7.13016666e+00 1.46e-05 5.55e-16 9.98e-07 0s 15 7.14285825e+00 7.14284445e+00 1.09e-13 3.68e-16 9.98e-10 0s 16 7.14285714e+00 7.14285713e+00 8.60e-14 3.33e-16 9.98e-13 0s Barrier solved model in 16 iterations and 0.14 seconds Optimal objective 7.14285714e+00 Root relaxation: objective 7.142857e+00, 5544 iterations, 0.23 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time 0 0 7.14286 0 39 37.00000 7.14286 80.7% - 1s H 0 0 8.0000000 7.14286 10.7% - 1s Explored 0 nodes (10865 simplex iterations) in 1.57 seconds Thread count was 1 (of 8 available processors) Optimal solution found (tolerance 0.00e+00) Best objective 8.000000000000e+00, best bound 8.000000000000e+00, gap 0.0% Preprocessing time: 0.40 seconds Gurobi run time: 1.57 seconds Total run time: 1.97 seconds Objective: 8 Solution: 1 x [12, 15, 21, 34, 35, 39, 40] 1 x [1, 2, 3, 20, 22, 23, 31] 1 x [7, 10, 15, 18, 19, 26] 1 x [4, 18, 24, 25, 41] 1 x [8, 14, 17, 29, 32, 36, 38] 1 x [9, 12, 16, 27, 37, 44, 45] 1 x [5, 6, 11, 28, 30, 43] 1 x [1, 13, 33, 42, 44]