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FOCS
1998
IEEE

The Finite Capacity Dial-A-Ride Problem

14 years 3 months ago
The Finite Capacity Dial-A-Ride Problem
In the Finite Capacity Dial-a-Ride problem the input is a metric space, a set of objects {di}, each specifying a source si and a destination ti, and an integer k--the capacity of the vehicle used for making the deliveries. The goal is to compute a shortest tour for the vehicle in which all objects can be delivered from their sources to their destinations while ensuring that the vehicle carries at most k objects at any point in time. In the preemptive version an object may be dropped at intermediate locations and picked up later and delivered. Let N be the number of nodes in the input graph. Charikar and Raghavachari [FOCS '98] gave a min{O(log N), O(k)}-approximation algorithm for the preemptive version of the problem. In this paper we show that the preemptive Finite Capacity Dial-a-Ride problem has no min{O(log1/4N), k1}-approximation algorithm for any > 0 unless all problems in NP can be solved by randomized algorithms with expected running time O(npolylogn ).
Moses Charikar, Balaji Raghavachari
Added 04 Aug 2010
Updated 04 Aug 2010
Type Conference
Year 1998
Where FOCS
Authors Moses Charikar, Balaji Raghavachari
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