S-20-50-3-3.mps.gz の問題を Gurobi 3.0.1 を用いて 9146 秒ほど解いてみたのだが、gap が 1.27% にしか減らないので、このまま解けるまで継続して実行することにした。やはり以前思っていたよりも難しい問題のようだ。
4979886 4263630 875146.194 113 137 875389.973 864275.516 1.27% 32.9 9135s
4982953 4266170 875274.113 106 134 875389.973 864275.926 1.27% 32.9 9140s
Cutting planes:
Gomory: 26
Cover: 42
Implied bound: 53
Flow cover: 632
Flow path: 1513
Explored 4985658 nodes (163987549 simplex iterations) in 9146.06 seconds
Thread count was 24 (of 24 available processors)
Solve interrupted
Best objective 8.7538997271e+05, best bound 8.6427598759e+05, gap 1.2696%
4979886 4263630 875146.194 113 137 875389.973 864275.516 1.27% 32.9 9135s
4982953 4266170 875274.113 106 134 875389.973 864275.926 1.27% 32.9 9140s
Cutting planes:
Gomory: 26
Cover: 42
Implied bound: 53
Flow cover: 632
Flow path: 1513
Explored 4985658 nodes (163987549 simplex iterations) in 9146.06 seconds
Thread count was 24 (of 24 available processors)
Solve interrupted
Best objective 8.7538997271e+05, best bound 8.6427598759e+05, gap 1.2696%