Parallel Algorithms with Optimal Speedup for Bounded Treewidth
نویسندگان
چکیده
منابع مشابه
Parallel Algorithms with Optimal Speedup for Bounded Treewidth
We describe the rst parallel algorithm with optimal speedup for constructing minimum-width tree decompositions of graphs of bounded treewidth. On n-vertex input graphs, the algorithm works in O((logn)) time using O(n) operations on the EREW PRAM. We also give faster parallel algorithms with optimal speedup for the problem of deciding whether the treewidth of an input graph is bounded by a given...
متن کاملKnown Algorithms on Graphs on Bounded Treewidth are Probably Optimal
We obtain a number of lower bounds on the running time of algorithms solving problems on graphs of bounded treewidth. We prove the results under the Strong Exponential Time Hypothesis of Impagliazzo and Paturi. In particular, assuming that SAT cannot be solved in (2−ǫ)m time, we show that for any ǫ > 0; • INDEPENDENT SET cannot be solved in (2 − ǫ)tw(G)|V (G)| time, • DOMINATING SET cannot be s...
متن کاملParallel Algorithms for Treewidth Two
In this paper we present a parallel algorithm that decides whether a graph G has treewidth at most two, and if so, construct a tree decomposition or path decomposition of minimum width of G. The algorithm uses O(n) operations and O(logn log n) time on an EREW PRAM, or O(logn) time on a CRCW PRAM. The algorithm makes use of the resemblance between series parallel graphs and partial two-trees. It...
متن کاملImproved Steiner Tree Algorithms for Bounded Treewidth
We propose a new algorithm that solves the Steiner tree problem on graphs with vertex set V to optimality in O(B tw+2 · tw · |V |) time, where tw is the graph’s treewidth and the Bell number Bk is the number of partitions of a k-element set. This is a linear time algorithm for graphs with fixed treewidth and a polynomial algorithm for tw = O(log |V |/ log log |V |). While being faster than the ...
متن کاملAlgorithms for Graphs of (Locally) Bounded Treewidth
Many real-life problems can be modeled by graph-theoretic problems. These graph problems are usually NP-hard and hence there is no efficient algorithm for solving them, unless P= NP. One way to overcome this hardness is to solve the problems when restricted to special graphs. Trees are one kind of graph for which several NP-complete problems can be solved in polynomial time. Graphs of bounded t...
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: 1998
ISSN: 0097-5397,1095-7111
DOI: 10.1137/s0097539795289859