current bounds on the number of colors: 0 -- 54 Gurobi 5.0.1 (linux64) logging started Thu Dec 13 19:36:33 2012 Optimize a model with 4428 rows, 1620 columns and 14580 nonzeros Presolve time: 0.02s Presolved: 4428 rows, 1620 columns, 14580 nonzeros Variable types: 0 continuous, 1620 integer (1620 binary) Root relaxation: objective 0.000000e+00, 131 iterations, 0.00 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time * 0 0 0 0.0000000 0.00000 0.0% - 0s Explored 0 nodes (252 simplex iterations) in 0.03 seconds Thread count was 1 (of 16 available processors) Optimal solution found (tolerance 1.00e-04) Best objective 0.000000000000e+00, best bound 0.000000000000e+00, gap 0.0% current bounds on the number of colors: 0 -- 27 Gurobi 5.0.1 (linux64) logging started Thu Dec 13 19:36:33 2012 Optimize a model with 2160 rows, 864 columns and 7020 nonzeros Presolve time: 0.01s Presolved: 2160 rows, 864 columns, 7020 nonzeros Variable types: 0 continuous, 864 integer (864 binary) Root relaxation: objective 0.000000e+00, 109 iterations, 0.00 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time * 0 0 0 0.0000000 0.00000 0.0% - 0s Explored 0 nodes (188 simplex iterations) in 0.01 seconds Thread count was 1 (of 16 available processors) Optimal solution found (tolerance 1.00e-04) Best objective 0.000000000000e+00, best bound 0.000000000000e+00, gap 0.0% current bounds on the number of colors: 0 -- 13 Gurobi 5.0.1 (linux64) logging started Thu Dec 13 19:36:33 2012 Optimize a model with 1026 rows, 486 columns and 3240 nonzeros Presolve time: 0.00s Presolved: 1026 rows, 486 columns, 3240 nonzeros Variable types: 0 continuous, 486 integer (486 binary) Root relaxation: objective 0.000000e+00, 113 iterations, 0.00 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time * 0 0 0 0.0000000 0.00000 0.0% - 0s Explored 0 nodes (200 simplex iterations) in 0.01 seconds Thread count was 1 (of 16 available processors) Optimal solution found (tolerance 1.00e-04) Best objective 0.000000000000e+00, best bound 0.000000000000e+00, gap 0.0% current bounds on the number of colors: 0 -- 6 Gurobi 5.0.1 (linux64) logging started Thu Dec 13 19:36:33 2012 Optimize a model with 540 rows, 324 columns and 1620 nonzeros Presolve time: 0.00s Presolved: 540 rows, 324 columns, 1620 nonzeros Variable types: 0 continuous, 324 integer (324 binary) Root relaxation: objective 0.000000e+00, 126 iterations, 0.00 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time 0 0 0.00000 0 102 - 0.00000 - - 0s 0 0 0.00000 0 94 - 0.00000 - - 0s 0 0 0.00000 0 144 - 0.00000 - - 0s 0 0 0.00000 0 150 - 0.00000 - - 0s 0 0 infeasible 0 - 0.10000 - - 0s Cutting planes: Gomory: 1 Zero half: 129 Explored 0 nodes (1700 simplex iterations) in 0.08 seconds Thread count was 1 (of 16 available processors) Model objective exceeds cutoff Best objective -, best bound 1.000000000000e+00, gap - current bounds on the number of colors: 3 -- 6 Gurobi 5.0.1 (linux64) logging started Thu Dec 13 19:36:33 2012 Optimize a model with 702 rows, 378 columns and 2160 nonzeros Presolve time: 0.00s Presolved: 702 rows, 378 columns, 2160 nonzeros Variable types: 0 continuous, 378 integer (378 binary) Root relaxation: objective 0.000000e+00, 121 iterations, 0.00 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time 0 0 0.00000 0 28 - 0.00000 - - 0s H 0 0 0.0000000 0.00000 0.0% - 0s Explored 0 nodes (542 simplex iterations) in 0.01 seconds Thread count was 1 (of 16 available processors) Optimal solution found (tolerance 1.00e-04) Best objective 0.000000000000e+00, best bound 0.000000000000e+00, gap 0.0% optimal solution found: number of colors: 4