Encoding Two-Dimensional Range Top-k Queries
نویسندگان
چکیده
We consider various encodings that support range Top-k queries on a two-dimensional array containing elements from a total order. For an m × n array, with m ≤ n, we first propose an almost optimal encoding for answering one-sided Top-k queries, whose query range is restricted to [1 . . .m][1 . . . a], for 1 ≤ a ≤ n. Next, we propose an encoding for the general Top-k queries that takes m2 lg ((k+1)n n ) + m lgm + o(n) bits. This generalizes the one-dimensional Top-k encoding of Gawrychowski and Nicholson [ICALP, 2015]. Finally, for a 2× n array, we obtain a 2 lg (3n n ) + 3n+ o(n)-bit encoding for answering Top-2 queries. 1998 ACM Subject Classification E.1 Data Structures
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