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Pagh's problem

From Wikipedia, the free encyclopedia

Pagh's problem is a data structure problem often used [1][2] when studying lower bounds in computer science named after Rasmus Pagh. Mihai Pătrașcu was the first to give lower bounds for the problem.[3] In 2021 it was shown that, given popular conjectures, the naive linear time algorithm is optimal.[4]

Definition

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We are given as inputs subsets over a universe .

We must accept updates of the following kind: Given a pointer to two subsets and , create a new subset .

After each update, we must output whether the new subset is empty or not.

References

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  1. Abboud, Amir, and Virginia Vassilevska Williams. "Popular conjectures imply strong lower bounds for dynamic problems." 2014 IEEE 55th Annual Symposium on Foundations of Computer Science. IEEE, 2014.
  2. Chen, Lijie, et al. "Nearly Optimal Separation Between Partially and Fully Retroactive Data Structures." 16th Scandinavian Symposium and Workshops on Algorithm Theory. 2018.
  3. Patrascu, Mihai. "Towards polynomial lower bounds for dynamic problems." Proceedings of the forty-second ACM symposium on Theory of computing. 2010.
  4. Henzinger, Monika, et al. "Unifying and strengthening hardness for dynamic problems via the online matrix-vector multiplication conjecture." Proceedings of the forty-seventh annual ACM symposium on Theory of computing. 2015.