These are Steiner arborescense problems (directed Steiner problems) from a genetic context. For more information see JKCMAKSFB00 . The graphs in these instances are layered (only have forward arcs).

The description of the file format is not jet finished. If you have any questions, please send an email.The files can be found in the download section.

Name | |V| | |E| | |T| | DC | Opt |
---|---|---|---|---|---|

gene181 | 267 | 355 | 25 | Ps | 88 |

gene1 | 267 | 355 | 25 | Ps | 88 |

gene425 | 425 | 554 | 86 | Ps | 214 |

gene42 | 335 | 456 | 43 | Ps | 126 |

gene442 | 442 | 594 | 86 | Ps | 207 |

gene575 | 575 | 824 | 86 | Ps | 207 |

gene602 | 602 | 858 | 86 | Ps | 209 |

gene61a | 395 | 512 | 82 | Ps | 205 |

gene61b | 570 | 808 | 82 | Ps | 199 |

gene61c | 549 | 790 | 82 | Ps | 196 |

gene61f | 412 | 552 | 82 | Ps | 198 |

The column **DC** classifies the difficulty of the instance.

- L
- Solvable by usage of local preprocessing. Typical examples are the SD-Test, BD-n Tests and FST computations. Neither a global upper nor lower bound needs to be computed.
- P
- Solvable by polynomial time algorithms, like dual ascent in combination with primal heuristic, a integral LP formulation or advanced preprocessing like reduced cost criteria or the RCR-Test.
- NP
- No polynomial time algorithm is known. Use of an exponential time enumeration sceme like Branch-and-Bound is neccessary.

The letter after class gives an impression how long it takes to solve
the problem using state-of-the-art soft- and hardware.
**s**ecounds means less than a minute (this includes
instances which can be solved in fractions of a second).
**m**inutes means less than an hour. **h**ours is less than a
day and **d**ays is less than a week. **w**eeks mean it takes
really a long time to solve this instance.
**?** means the instance is not solved or the time is not known.

If the number in the **Opt** column is written in *italics*
the optimum is not known. The number given is the best know upper bound.

Last Update : 2015/02/11 11:57:20 $ by Thorsten Koch

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