### Abstract

Given a matroid, where each element has a realvalued cost and is colored red or green; we seek a minimum cost base with exactly q red elements. This is a simple case of the matroid intersection problem. A general algorithm is presented. Its efficiency is illustrated in the special case of finding a minimum spanning tree with q red edges; the time is O(m log log n + n α (n,n) log n). Efficient algorithms are also given for job scheduling matroids and partition matroids. An algorithm is given for finding a minimum spanning tree where a vertex r has prespecified degree; it shows this problem is equivalent to finding a minimum spanning tree, without the degree constraint. An algorithm is given for finding a minimum spanning tree on a directed graph, where the given root r has prespecified degree; the time is O(m log n), the same as for the problem without the degree constraint.

Original language | English (US) |
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Article number | 4568015 |

Pages (from-to) | 196-204 |

Number of pages | 9 |

Journal | Proceedings - Annual IEEE Symposium on Foundations of Computer Science, FOCS |

DOIs | |

State | Published - Jan 1 1979 |

Externally published | Yes |

Event | 20th Annual Symposium on Foundations of Computer Science, FOCS 1979 - San Juan, United States Duration: Oct 29 1979 → Oct 31 1979 |

### All Science Journal Classification (ASJC) codes

- Computer Science(all)