A TDI System and its Application to Approximation Algorithms
نویسندگان
چکیده
We obtain a necessary and su cient condition for tournaments to possess a min-max relation on packing and covering directed cycles, together with strongly polynomial time algorithms for the feedback vertex set problem and the cycle packing problem in this class of tournaments; the condition and the algorithms are all based on a totally dual integral system, a theoretical framework introduced by Edmonds and Giles for establishing min-max results. As a consequence, we nd a 2:5-approximation polynomial time algorithm for the feedback vertex set problem in any tournament.
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تاریخ انتشار 1998