Range Queries over Untangled Chains
نویسندگان
چکیده
We present a practical implementation of the first adaptive data structure for orthogonal range queries in 2D [Arroyuelo et al., ISAAC 2009]. The structure is static, requires only linear space for its representation, and can even be made implicit. The running time for a query is O(k lg n+m), where k is the number of non-crossing monotonic chains in which we can partition the set of points, and m is the size of the output. The space consumption of our implementation is 2n + o(n) words. The experimental results show that this structure is competitive with the state of the art. We also present an alternative construction algorithm for our structure, which in practice outperforms the original proposal by orders of magnitude.
منابع مشابه
Untangled Monotonic Chains and Adaptive Range Search
We present the first adaptive data structure for two-dimensional orthogonal range search. Our data structure is adaptive in the sense that it gives improved search performance for data with more inherent sortedness. Given n points in the plane, it can answer range queries in O(k logn+m) time, where m is the number of points in the output and k is the minimum number of monotonic chains into whic...
متن کاملCompositional State Space Reduction Using Untangled Actions
We propose a compositional technique for efficient verification of networks of parallel processes. It is based on an automatic analysis of LTSs of individual processes (using a failure-based equivalence which preserves divergences) that determines their sets of “conflict-free” actions, called untangled actions. Untangled actions are compositional, i.e. synchronisation on untangled actions will ...
متن کاملارائه روشی پویا جهت پاسخ به پرسوجوهای پیوسته تجمّعی اقتضایی
Data Streams are infinite, fast, time-stamp data elements which are received explosively. Generally, these elements need to be processed in an online, real-time way. So, algorithms to process data streams and answer queries on these streams are mostly one-pass. The execution of such algorithms has some challenges such as memory limitation, scheduling, and accuracy of answers. They will be more ...
متن کاملImplementing Range Queries with a Decentralized Balanced Tree Over DHTs
Range queries, retrieving all keys within a given range, is an important add-on for DHTs, as they rely only on exact key matching lookup. In this paper we support range queries by way of a tree algorithm, Decentralized Balanced Tree, that runs over any DHT system. Our algorithm is based on the B+ tree design that efficiently stores clustered data while maintaining a balanced load on hosts. The ...
متن کامل