current bounds on the number of colors: 0 -- 12 Gurobi 5.0.1 (linux64) logging started Thu Dec 13 17:55:53 2012 Optimize a model with 228 rows, 108 columns and 720 nonzeros Presolve time: 0.00s Presolved: 228 rows, 108 columns, 720 nonzeros Variable types: 0 continuous, 108 integer (108 binary) Root relaxation: objective 0.000000e+00, 27 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 (52 simplex iterations) in 0.00 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 17:55:53 2012 Optimize a model with 120 rows, 72 columns and 360 nonzeros Presolve time: 0.00s Presolved: 120 rows, 72 columns, 360 nonzeros Variable types: 0 continuous, 72 integer (72 binary) Root relaxation: objective 0.000000e+00, 25 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 16 - 0.00000 - - 0s 0 0 0.00000 0 22 - 0.00000 - - 0s 0 0 infeasible 0 - 0.10000 - - 0s Explored 0 nodes (180 simplex iterations) in 0.01 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 17:55:53 2012 Optimize a model with 156 rows, 84 columns and 480 nonzeros Presolve time: 0.00s Presolved: 156 rows, 84 columns, 480 nonzeros Variable types: 0 continuous, 84 integer (84 binary) Root relaxation: objective 0.000000e+00, 25 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 16 - 0.00000 - - 0s H 0 0 0.0000000 0.00000 0.0% - 0s Explored 0 nodes (125 simplex iterations) in 0.00 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