Build (method = -2) #dp: 1017 Step-3' Graph: 62 vertices and 179 arcs (0.00s) Step-4' Graph: 7 vertices and 69 arcs (0.00s) #V4/#V3 = 0.11 #A4/#A3 = 0.39 Ready! (0.00s) Optimize a model with 27 rows, 70 columns and 200 nonzeros Presolve removed 3 rows and 3 columns Presolve time: 0.00s Presolved: 24 rows, 67 columns, 193 nonzeros Variable types: 0 continuous, 67 integer (6 binary) Found heuristic solution: objective 196.0000000 Found heuristic solution: objective 179.0000000 Optimize a model with 24 rows, 67 columns and 193 nonzeros Presolved: 24 rows, 67 columns, 193 nonzeros Root barrier log... Ordering time: 0.00s Barrier statistics: AA' NZ : 6.800e+01 Factor NZ : 2.620e+02 Factor Ops : 3.836e+03 (less than 1 second per iteration) Threads : 1 Objective Residual Iter Primal Dual Primal Dual Compl Time 0 6.70850619e+02 -8.92550584e+02 5.65e+01 3.26e-02 2.23e+01 0s 1 1.98548410e+02 -2.49658997e+02 1.72e+00 4.44e-16 3.30e+00 0s 2 9.26167471e+01 2.71580441e+00 1.03e-01 2.11e-15 6.03e-01 0s 3 6.72613776e+01 6.13339452e+01 5.02e-04 3.33e-16 3.92e-02 0s 4 6.66805286e+01 6.66087913e+01 2.49e-14 2.23e-16 4.75e-04 0s 5 6.66666692e+01 6.66666639e+01 2.72e-14 2.22e-16 3.48e-08 0s 6 6.66666667e+01 6.66666667e+01 3.70e-14 2.22e-16 3.87e-14 0s Barrier solved model in 6 iterations and 0.00 seconds Optimal objective 6.66666667e+01 Root relaxation: objective 6.666667e+01, 52 iterations, 0.00 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time 0 0 66.66667 0 4 179.00000 66.66667 62.8% - 0s H 0 0 67.0000000 66.66667 0.50% - 0s Explored 0 nodes (62 simplex iterations) in 0.00 seconds Thread count was 1 (of 8 available processors) Optimal solution found (tolerance 0.00e+00) Best objective 6.700000000000e+01, best bound 6.700000000000e+01, gap 0.0% Preprocessing time: 0.01 seconds Gurobi run time: 0.00 seconds Total run time: 0.01 seconds Objective: 67 Solution: 14 x [1, 3, 19] 1 x [1, 4, 8] 3 x [1, 12, 17] 1 x [10, 18] 10 x [9, 11, 16] 1 x [5, 7, 20] 5 x [2, 6, 20] 7 x [11, 12, 17] 2 x [9, 11, 15] 4 x [4, 6, 19] 18 x [5, 13, 18] 1 x [8, 9, 14]