Build (method = -2) #dp: 68 Step-3' Graph: 18 vertices and 47 arcs (0.00s) Step-4' Graph: 10 vertices and 31 arcs (0.00s) #V4/#V3 = 0.56 #A4/#A3 = 0.66 Ready! (0.00s) Optimize a model with 20 rows, 32 columns and 80 nonzeros Presolve removed 12 rows and 20 columns Presolve time: 0.00s Presolved: 8 rows, 12 columns, 29 nonzeros Variable types: 0 continuous, 12 integer (0 binary) Found heuristic solution: objective 71.0000000 Optimize a model with 8 rows, 12 columns and 29 nonzeros Presolved: 8 rows, 12 columns, 29 nonzeros Root barrier log... Ordering time: 0.00s Barrier statistics: AA' NZ : 1.400e+01 Factor NZ : 3.600e+01 Factor Ops : 2.040e+02 (less than 1 second per iteration) Threads : 1 Objective Residual Iter Primal Dual Primal Dual Compl Time 0 1.00056570e+02 -6.31117503e+01 1.54e+01 1.11e-16 1.09e+01 0s 1 6.65493242e+01 2.46066421e+01 3.55e-15 3.33e-16 1.45e+00 0s 2 5.62873073e+01 5.22501316e+01 3.55e-15 5.55e-17 1.39e-01 0s 3 5.55064072e+01 5.54908441e+01 3.55e-15 2.22e-16 5.37e-04 0s 4 5.55000064e+01 5.54999908e+01 1.80e-15 2.22e-16 5.37e-07 0s 5 5.55000000e+01 5.55000000e+01 7.11e-15 1.11e-16 5.37e-13 0s Barrier solved model in 5 iterations and 0.00 seconds Optimal objective 5.55000000e+01 Root relaxation: objective 5.550000e+01, 5 iterations, 0.00 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time 0 0 55.50000 0 4 71.00000 55.50000 21.8% - 0s H 0 0 56.0000000 55.50000 0.89% - 0s Explored 0 nodes (5 simplex iterations) in 0.00 seconds Thread count was 1 (of 8 available processors) Optimal solution found (tolerance 0.00e+00) Best objective 5.600000000000e+01, best bound 5.600000000000e+01, gap 0.0% Preprocessing time: 0.01 seconds Gurobi run time: 0.00 seconds Total run time: 0.01 seconds Objective: 56 Solution: 14 x [1] 3 x [2, 10] 10 x [3, 9] 8 x [4, 8] 1 x [5] 4 x [5, 6] 12 x [5, 7] 1 x [7, 8] 3 x [7, 8, 9]