Build (method = -2) #dp: 9269 Step-3' Graph: 1261 vertices and 3776 arcs (0.06s) Step-4' Graph: 896 vertices and 3046 arcs (0.07s) #V4/#V3 = 0.71 #A4/#A3 = 0.81 Ready! (0.07s) Optimize a model with 915 rows, 3047 columns and 7353 nonzeros Presolve removed 275 rows and 523 columns Presolve time: 0.06s Presolved: 640 rows, 2524 columns, 7084 nonzeros Variable types: 0 continuous, 2524 integer (359 binary) Optimize a model with 640 rows, 2524 columns and 7084 nonzeros Presolved: 640 rows, 2524 columns, 7084 nonzeros Root barrier log... Ordering time: 0.01s Barrier statistics: AA' NZ : 4.749e+03 Factor NZ : 2.776e+04 (roughly 2 MBytes of memory) Factor Ops : 2.044e+06 (less than 1 second per iteration) Threads : 1 Objective Residual Iter Primal Dual Primal Dual Compl Time 0 4.84032669e+02 -2.63386501e+04 3.79e+04 2.04e-02 5.07e+01 0s 1 1.60622087e+02 -1.71201897e+04 5.86e+03 5.78e-02 9.98e+00 0s 2 1.04275425e+02 -5.73358771e+03 1.29e+03 1.75e-02 2.40e+00 0s 3 7.13946955e+01 -1.06948591e+03 1.42e+02 1.78e-15 3.39e-01 0s 4 6.17565183e+01 -3.70134875e+02 4.09e+01 1.22e-15 1.12e-01 0s 5 4.99103032e+01 -2.33182222e+02 1.27e+01 8.74e-16 6.29e-02 0s 6 4.30190440e+01 -1.13731944e+02 4.77e+00 6.59e-16 3.30e-02 0s 7 3.43197976e+01 -3.94733181e+01 1.73e+00 6.31e-16 1.52e-02 0s 8 2.99926260e+01 5.61116927e+00 4.33e-01 5.76e-16 4.94e-03 0s 9 2.85652144e+01 1.75237438e+01 1.41e-01 4.94e-16 2.22e-03 0s 10 2.80308008e+01 2.70237241e+01 5.70e-03 7.31e-16 2.01e-04 0s 11 2.80000196e+01 2.79995964e+01 1.28e-06 6.60e-16 8.42e-08 0s 12 2.80000000e+01 2.79999996e+01 4.11e-13 3.55e-16 8.42e-11 0s 13 2.80000000e+01 2.80000000e+01 6.71e-13 3.87e-16 1.10e-16 0s Barrier solved model in 13 iterations and 0.06 seconds Optimal objective 2.80000000e+01 Root relaxation: objective 2.800000e+01, 1356 iterations, 0.07 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time * 0 0 0 28.0000000 28.00000 0.0% - 0s Explored 0 nodes (1738 simplex iterations) in 0.36 seconds Thread count was 1 (of 8 available processors) Optimal solution found (tolerance 0.00e+00) Best objective 2.800000000000e+01, best bound 2.800000000000e+01, gap 0.0% Preprocessing time: 0.09 seconds Gurobi run time: 0.36 seconds Total run time: 0.44 seconds Objective: 28 Solution: 2 x [1, 2, 4, 7, 11, 13] 1 x [1, 2, 4, 10, 11, 17, 18, 19] 1 x [1, 2, 4, 11, 13, 17, 18, 19] 2 x [1, 2, 5, 10, 11, 12, 13] 2 x [1, 2, 6, 9, 11, 13, 17, 19] 1 x [1, 2, 6, 11, 13, 17, 18, 19] 1 x [1, 2, 11, 13, 17, 18, 19] 2 x [1, 4, 6, 11, 13, 14, 15] 2 x [1, 4, 9, 10, 11, 12, 16, 17] 2 x [1, 4, 11, 17, 18, 19] 2 x [1, 7, 9, 10, 11, 12, 13, 16, 17] 1 x [1, 9, 11, 13, 19] 1 x [2, 3, 11, 17, 18, 19] 2 x [2, 4, 6, 7, 8, 11] 2 x [2, 4, 9, 11, 13, 19] 2 x [4, 7, 9, 11, 12, 13, 17, 18, 19] 2 x [4, 10, 11, 13, 17, 18, 19]