Approximation algorithm for the multicovering problem
نویسندگان
چکیده
Let $$\mathcal {H}=(V,\mathcal {E})$$ be a hypergraph with maximum edge size $$\ell $$ and degree $$\varDelta . For given positive integers $$b_v$$ , $$v\in V$$ set multicover in {H}$$ is of edges $$C \subseteq \mathcal {E}$$ such that every vertex v V belongs to at least C. Set the problem finding minimum-cardinality multicover. Peleg, Schechtman Wool conjectured for any fixed $$b:=\min _{v\in V}b_{v}$$ not approximable within ratio less than $$\delta :=\varDelta -b+1$$ unless {P}=\mathcal {NP}$$ Hence it’s challenge explore which classes conjecture doesn’t hold. We present polynomial time algorithm combines deterministic threshold conditioned randomized rounding steps. Our yields an approximation $$\max \left\{ \frac{148}{149}\delta \left( 1- \frac{ (b-1)e^{\frac{\delta }{4}}}{94\ell } \right) \delta \right\} $$b\ge 2$$ \ge 3$$ result only improves over presented by El Ouali et al. (Algorithmica 74:574, 2016) but more general since we no restriction on parameter Moreover further $$\frac{5}{6}\delta hypergraphs \le (1+\epsilon )\bar{\ell }$$ $$\epsilon \in [0,\frac{1}{2}]$$ where $$\bar{\ell average size. The analysis this relies matching/covering duality due Ray-Chaudhuri (1960), convert into approximative form. second performance disprove Peleg large subclass hypergraphs.
منابع مشابه
the algorithm for solving the inverse numerical range problem
برد عددی ماتریس مربعی a را با w(a) نشان داده و به این صورت تعریف می کنیم w(a)={x8ax:x ?s1} ، که در آن s1 گوی واحد است. در سال 2009، راسل کاردن مساله برد عددی معکوس را به این صورت مطرح کرده است : برای نقطه z?w(a)، بردار x?s1 را به گونه ای می یابیم که z=x*ax، در این پایان نامه ، الگوریتمی برای حل مساله برد عددی معکوس ارانه می دهیم.
15 صفحه اولApproximation Algorithm for the Max-Cut Problem
In this project, we investigated several approximation algorithms for the Max-Cut problem. Our main approach to this problem is a semideenite program (GW) based algorithm that has a performance guarantee of at least 0.878 of the optimal cut. We also show that we can perform exhaustive local search on top of the GW to enhance the result. Our results show that the running time of the local search...
متن کامل)–Approximation Algorithm for the Stable Marriage Problem
We propose an approximation algorithm for the problem of finding a maximum stable matching when both ties and unacceptable partners are allowed in preference lists. Our algorithm achieves the approximation ratio 2− c logN N for an arbitrarily positive constant c, where N denotes the number of men in an input. This improves the trivial approximation ratio of two.
متن کامل{Approximation Algorithm for the Shortest Superstring Problem
Given a collection of strings S = fs1; : : : ; sng over an alphabet , a superstring of S is a string containing each si as a substring; that is, for each i, 1 i n, contains a block of jsij consecutive characters that match si exactly. The shortest superstring problem is the problem of nding a superstring of minimum length. The shortest superstring problem has applications in both data compressi...
متن کاملApproximation algorithm for the cyclic swap problem
Given two n-bit (cyclic) binary strings, A and B, represented on a circle (necklace instances). Let each sequence have the same number k of 1’s. We are interested in computing the cyclic swap distance between A and B, i.e., the minimum number of swaps needed to convert A into B, minimized over all rotations of B. We show that this distance may be approximated in O(n + k2) time.
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: Journal of Combinatorial Optimization
سال: 2021
ISSN: ['1573-2886', '1382-6905']
DOI: https://doi.org/10.1007/s10878-020-00688-9