Build (method = -2) #dp: 9257 Step-3' Graph: 168 vertices and 497 arcs (0.06s) Step-4' Graph: 25 vertices and 211 arcs (0.06s) #V4/#V3 = 0.15 #A4/#A3 = 0.42 Ready! (0.06s) Optimize a model with 64 rows, 212 columns and 590 nonzeros Presolve removed 6 rows and 8 columns Presolve time: 0.00s Presolved: 58 rows, 204 columns, 571 nonzeros Variable types: 0 continuous, 204 integer (105 binary) Found heuristic solution: objective 22.0000000 Optimize a model with 58 rows, 204 columns and 571 nonzeros Presolved: 58 rows, 204 columns, 571 nonzeros Root barrier log... Ordering time: 0.00s Barrier statistics: AA' NZ : 2.290e+02 Factor NZ : 6.830e+02 Factor Ops : 1.238e+04 (less than 1 second per iteration) Threads : 1 Objective Residual Iter Primal Dual Primal Dual Compl Time 0 2.05417909e+02 -3.42283139e+02 6.68e+01 3.90e-02 2.89e+00 0s 1 4.56270307e+01 -9.45396656e+01 8.62e-01 2.22e-16 3.60e-01 0s 2 2.04961383e+01 -2.16007969e-01 5.91e-03 6.41e-03 5.05e-02 0s 3 1.27859609e+01 1.03291226e+01 1.97e-04 1.70e-16 5.88e-03 0s 4 1.25012798e+01 1.24975520e+01 4.80e-14 1.11e-16 8.92e-06 0s 5 1.25000000e+01 1.25000000e+01 3.11e-14 1.13e-16 9.17e-12 0s Barrier solved model in 5 iterations and 0.00 seconds Optimal objective 1.25000000e+01 Root relaxation: objective 1.250000e+01, 129 iterations, 0.00 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time 0 0 12.50000 0 6 22.00000 12.50000 43.2% - 0s H 0 0 13.0000000 12.50000 3.85% - 0s Explored 0 nodes (165 simplex iterations) in 0.01 seconds Thread count was 1 (of 8 available processors) Optimal solution found (tolerance 0.00e+00) Best objective 1.300000000000e+01, best bound 1.300000000000e+01, gap 0.0% Preprocessing time: 0.07 seconds Gurobi run time: 0.01 seconds Total run time: 0.08 seconds Objective: 13 Solution: 1 x [7, 13, 14, 36] 1 x [12, 13, 33, 39] 1 x [11, 31, 34, 37] 1 x [9, 10, 36, 38] 1 x [1, 9, 15, 20] 1 x [2, 6, 8, 31] 1 x [5, 30, 30, 33] 1 x [4, 26, 27, 32] 1 x [3, 23, 24, 29] 1 x [1, 16, 22, 34] 1 x [17, 28, 38] 1 x [18, 21, 25, 35] 1 x [17, 19, 33]