Abstract
Random costs C(i, j) are assigned to the arcs of a complete directed graph on n labeled vertices. Given the cost matrix Cn = (C(i, J)), let Tk* = Tk*(Cn) be the spanning tree that has minimum cost among spanning trees with in-degree less than or equal to k. Since it is NP-hard to find Tk*, we instead consider an efficient algorithm that finds a near-optimal spanning tree Tka. If the edge costs are independent, with a common exponential(1) distribution, then, as n ? 8, E(Cost(Tka) = E(Cost(Tk*) + o(1). Upper and lower bounds for E(Cost(Tk*)) are also obtained for k = 2.
Original language | English |
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Pages (from-to) | 148-180 |
Number of pages | 33 |
Journal | Algorithmica |
Volume | 29 |
Issue number | 1-2 |
Publication status | Published - Jan 2001 |
Keywords
- Approximation algorithm
- Assignment problem
- Random mapping
- Spanning tree