Build (method = -2) #dp: 1539 Step-3' Graph: 199 vertices and 936 arcs (0.01s) Step-4' Graph: 161 vertices and 860 arcs (0.01s) #V4/#V3 = 0.81 #A4/#A3 = 0.92 Ready! (0.01s) Optimize a model with 181 rows, 861 columns and 2272 nonzeros Presolve removed 27 rows and 50 columns Presolve time: 0.01s Presolved: 154 rows, 811 columns, 2200 nonzeros Variable types: 0 continuous, 811 integer (58 binary) Found heuristic solution: objective 181.0000000 Found heuristic solution: objective 165.0000000 Found heuristic solution: objective 144.0000000 Optimize a model with 154 rows, 811 columns and 2200 nonzeros Presolved: 154 rows, 811 columns, 2200 nonzeros Root barrier log... Ordering time: 0.00s Barrier statistics: AA' NZ : 1.286e+03 Factor NZ : 4.269e+03 Factor Ops : 1.606e+05 (less than 1 second per iteration) Threads : 1 Objective Residual Iter Primal Dual Primal Dual Compl Time 0 2.80330078e+03 -1.62525062e+04 1.69e+04 1.83e-01 9.62e+01 0s 1 8.55758959e+02 -7.82883460e+03 2.95e+03 8.88e-16 1.84e+01 0s 2 3.19987129e+02 -2.94473357e+03 3.67e+02 1.11e-15 3.25e+00 0s 3 2.00371582e+02 -5.07647633e+02 3.53e+01 8.55e-15 5.04e-01 0s 4 1.74882616e+02 -1.76875085e+02 1.11e+01 4.22e-15 2.28e-01 0s 5 1.55605809e+02 -6.84495310e+01 7.14e+00 2.11e-15 1.44e-01 0s 6 1.29761618e+02 1.02779033e+01 3.91e+00 8.88e-16 7.62e-02 0s 7 9.83650957e+01 3.75243627e+01 1.66e+00 3.33e-16 3.84e-02 0s 8 8.11076957e+01 6.52986898e+01 4.58e-01 3.40e-16 9.95e-03 0s 9 7.72406139e+01 7.02897931e+01 1.78e-01 3.33e-16 4.36e-03 0s 10 7.44488429e+01 7.29755687e+01 1.96e-02 3.33e-16 9.12e-04 0s 11 7.40052511e+01 7.39779088e+01 2.33e-04 2.25e-16 1.69e-05 0s 12 7.40000001e+01 7.39999999e+01 2.11e-09 3.43e-16 1.07e-10 0s Barrier solved model in 12 iterations and 0.01 seconds Optimal objective 7.40000001e+01 Root relaxation: objective 7.400000e+01, 244 iterations, 0.01 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time 0 0 74.00000 0 8 144.00000 74.00000 48.6% - 0s H 0 0 75.0000000 74.00000 1.33% - 0s H 0 0 74.0000000 74.00000 0.0% - 0s Explored 0 nodes (368 simplex iterations) in 0.05 seconds Thread count was 1 (of 8 available processors) Optimal solution found (tolerance 0.00e+00) Best objective 7.400000000000e+01, best bound 7.400000000000e+01, gap 0.0% Preprocessing time: 0.02 seconds Gurobi run time: 0.05 seconds Total run time: 0.07 seconds Objective: 74 Solution: 7 x [8, 17] 8 x [8, 20] 4 x [1, 3] 2 x [1, 2] 8 x [1, 2, 19] 1 x [1, 7, 18] 1 x [12, 18, 20] 1 x [12, 20, 20] 1 x [10, 13, 14] 4 x [11, 13, 16] 5 x [6, 13, 18] 4 x [5, 9] 7 x [7, 9, 10] 8 x [4, 5, 14] 2 x [5, 10, 14] 1 x [6, 16, 18] 5 x [16, 16, 17] 1 x [15, 16, 16] 3 x [6, 6, 7, 7] 1 x [6, 6, 11]