A Randomized Queueless Algorithm for Breadth-First Search

First Come First Served is a policy that is accepted for implementing fairness in a number of application domains such as scheduling in Operating Systems [28, 11], scheduling web requests and so on. We also have orthogonal applications of FCFS policies in proving correctness of search algorithms such as Breadth-First Search and the Bellman-Ford FIFO implementation for finding single-source shortest paths [2], program verification [12] and static analysis [25, 24]. The principal data structure used in implementing FCFS policies is the queue, which is realized either through a circular array or a linked list. The question of interest then, is whether queues are required to implement FCFS policies; this paper provides empirical evidence answering this question in the negative. The principal contribution of this paper is the development of a randomized algorithm to implement approximate FCFS policies without queues. The 

• Type: Journal
• Year: 2008
• Where: ISCA
• Authors: K. Subramani, Kamesh Madduri
• Keywords: Bellman-Ford FIFO Implementation, FCFS Policies, Hardware, ISCA 2008, Single-source Shortest Paths