The Greedy Spanner Is Existentially Optimal
نویسندگان
چکیده
منابع مشابه
\delta -Greedy t-spanner
We introduce a new geometric spanner, δ-Greedy, whose construction is based on a generalization of the known Path-Greedy and Gap-Greedy spanners. The δ-Greedy spanner combines the most desirable properties of geometric spanners both in theory and in practice. More specifically, it has the same theoretical and practical properties as the Path-Greedy spanner: a natural definition, small degree, l...
متن کاملThe Weight of the Greedy Graph Spanner
We calculate a near-optimal upper bound on the weight of a graph spanner produced by the (so called) Greedy Spanner Algorithm on a weighted graph. Our upper bound is independent of the magnitude of the weights in the graph, and it matches the known lower bound up to a O(log(n)) for n-vertex graphs. We also update the bound on the size of the spanner, and bound above the weight of any non-MST ed...
متن کاملGreedy Recommending Is Not Always Optimal
Recommender systems help users to find objects or documents on web sites. In many cases it is not easy to know in advance by whom and for what purpose a web site will be used. This makes it difficult for many applications to define adequate recommendations in advance. Therefore recommendations are typically generated dynamically. Recommendations are based on analysis of user data (social filter...
متن کاملGreedy Is an Almost Optimal Deque
In this paper we extend the geometric binary search tree (BST) model of Demaine, Harmon, Iacono, Kane, and Pǎtraşcu (DHIKP) to accommodate for insertions and deletions. Within this extended model, we study the online Greedy BST algorithm introduced by DHIKP. Greedy BST is known to be equivalent to a maximally greedy (but inherently offline) algorithm introduced independently by Lucas in 1988 an...
متن کاملOnline Submodular Welfare Maximization: Greedy is Optimal
We prove that no online algorithm (even randomized, against an oblivious adversary) is better than 1/2competitive for welfare maximization with coverage valuations, unless NP = RP . Since the Greedy algorithm is known to be 1/2-competitive for monotone submodular valuations, of which coverage is a special case, this proves that Greedy provides the optimal competitive ratio. On the other hand, w...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: SIAM Journal on Computing
سال: 2020
ISSN: 0097-5397,1095-7111
DOI: 10.1137/18m1210678