Build (method = -2) #dp: 8688 Step-3' Graph: 173 vertices and 512 arcs (0.06s) Step-4' Graph: 18 vertices and 202 arcs (0.06s) #V4/#V3 = 0.10 #A4/#A3 = 0.39 Ready! (0.06s) Optimize a model with 60 rows, 203 columns and 577 nonzeros Presolve removed 5 rows and 6 columns Presolve time: 0.00s Presolved: 55 rows, 197 columns, 563 nonzeros Variable types: 0 continuous, 197 integer (131 binary) Found heuristic solution: objective 15.0000000 Optimize a model with 55 rows, 197 columns and 563 nonzeros Presolved: 55 rows, 197 columns, 563 nonzeros Root barrier log... Ordering time: 0.00s Barrier statistics: AA' NZ : 2.140e+02 Factor NZ : 6.860e+02 Factor Ops : 1.325e+04 (less than 1 second per iteration) Threads : 1 Objective Residual Iter Primal Dual Primal Dual Compl Time 0 2.14547481e+02 -3.09323258e+02 4.33e+01 2.96e-02 2.70e+00 0s 1 4.13519502e+01 -7.40697518e+01 3.57e-01 1.67e-16 3.07e-01 0s 2 2.32332451e+01 -4.97195040e+00 2.90e-02 5.83e-16 7.23e-02 0s 3 1.31433298e+01 9.61832852e+00 2.01e-03 3.33e-16 8.79e-03 0s 4 1.25019591e+01 1.24912805e+01 1.23e-14 2.85e-16 2.66e-05 0s 5 1.25000000e+01 1.25000000e+01 5.08e-14 2.22e-16 2.81e-11 0s Barrier solved model in 5 iterations and 0.00 seconds Optimal objective 1.25000000e+01 Root relaxation: objective 1.250000e+01, 138 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 5 15.00000 12.50000 16.7% - 0s H 0 0 13.0000000 12.50000 3.85% - 0s Explored 0 nodes (179 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: 0.07 seconds Objective: 13 Solution: 2 x [6, 10, 16, 24] 1 x [1, 7, 9, 15] 1 x [12, 13, 14, 26] 1 x [12, 17, 18] 1 x [4, 10, 11] 1 x [4, 5, 8, 40] 1 x [2, 3, 38, 39] 1 x [29, 36, 41, 42] 1 x [23, 28, 34, 37] 1 x [21, 27, 32, 35] 1 x [20, 25, 30, 33] 1 x [19, 22, 26, 31]