Build (method = -2) #dp: 30945 Step-3' Graph: 3460 vertices and 10373 arcs (0.19s) Step-4' Graph: 1559 vertices and 6571 arcs (0.21s) #V4/#V3 = 0.45 #A4/#A3 = 0.63 Ready! (0.21s) Optimize a model with 1608 rows, 6572 columns and 16602 nonzeros Presolve removed 649 rows and 669 columns Presolve time: 0.08s Presolved: 959 rows, 5903 columns, 17414 nonzeros Variable types: 0 continuous, 5903 integer (4839 binary) Optimize a model with 959 rows, 5903 columns and 17414 nonzeros Presolve removed 28 rows and 28 columns Presolved: 931 rows, 5875 columns, 17553 nonzeros Root barrier log... Ordering time: 0.01s Barrier statistics: AA' NZ : 8.659e+03 Factor NZ : 3.412e+04 (roughly 3 MBytes of memory) Factor Ops : 2.529e+06 (less than 1 second per iteration) Threads : 1 Objective Residual Iter Primal Dual Primal Dual Compl Time 0 7.00388945e+02 -7.23785899e+03 1.41e+04 3.41e-01 5.04e+00 0s 1 1.64934609e+02 -3.37550628e+03 2.93e+03 1.70e-01 1.17e+00 0s 2 9.14249859e+01 -1.07777183e+03 4.62e+02 2.54e-02 2.23e-01 0s 3 3.70895764e+01 -1.46034016e+02 6.40e+01 8.80e-04 3.20e-02 0s 4 1.97811904e+01 -6.97801188e+01 1.42e+01 6.66e-16 1.10e-02 0s 5 1.42850715e+01 -2.46479603e+01 2.15e+00 5.55e-16 3.70e-03 0s 6 1.21907544e+01 -7.54856306e+00 5.68e-01 4.44e-16 1.74e-03 0s 7 1.09468799e+01 9.25130158e-01 2.74e-01 3.35e-16 8.76e-04 0s 8 8.63457294e+00 2.72857442e+00 9.49e-02 3.23e-16 5.11e-04 0s 9 7.20454509e+00 6.76448720e+00 1.93e-03 2.65e-16 3.76e-05 0s 10 7.00124628e+00 6.99952406e+00 3.95e-06 3.23e-16 1.47e-07 0s 11 7.00000125e+00 6.99999952e+00 4.11e-14 3.61e-16 1.47e-10 0s 12 7.00000000e+00 7.00000000e+00 1.39e-13 3.33e-16 3.00e-16 0s Barrier solved model in 12 iterations and 0.10 seconds Optimal objective 7.00000000e+00 Root relaxation: objective 7.000000e+00, 804 iterations, 0.11 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time * 0 0 0 7.0000000 7.00000 0.0% - 0s Explored 0 nodes (804 simplex iterations) in 0.23 seconds Thread count was 1 (of 8 available processors) Optimal solution found (tolerance 0.00e+00) Best objective 7.000000000000e+00, best bound 7.000000000000e+00, gap 0.0% Preprocessing time: 0.23 seconds Gurobi run time: 0.23 seconds Total run time: 0.46 seconds Objective: 7 Solution: 1 x [5, 14, 16, 25, 34, 36, 45] 1 x [6, 8, 17, 26, 35, 37, 46] 1 x [4, 13, 15, 24, 33, 42, 44] 1 x [7, 9, 18, 27, 29, 38, 47] 1 x [1, 10, 19, 28, 30, 39, 48] 1 x [2, 11, 20, 22, 31, 40, 49] 1 x [3, 12, 21, 23, 32, 41, 43]