Greedily Finding a Dense Subgraph
β Scribed by Yuichi Asahiro; Kazuo Iwama; Hisao Tamaki; Takeshi Tokuyama
- Book ID
- 102572802
- Publisher
- Elsevier Science
- Year
- 2000
- Tongue
- English
- Weight
- 144 KB
- Volume
- 34
- Category
- Article
- ISSN
- 0196-6774
No coin nor oath required. For personal study only.
β¦ Synopsis
Given an n-vertex graph with nonnegative edge weights and a positive integer k F n, our goal is to find a k-vertex subgraph with the maximum weight. We study the following greedy algorithm for this problem: repeatedly remove a vertex with the minimum weighted-degree in the currently remaining graph, until exactly k vertices are left. We derive tight bounds on the worst case approximation ratio R Ε½ . 2 Ε½ y1 r3 . Ε½ . 2 of this greedy algorithm: 1r2
For k s nr2, for example, these bounds are 9r4 " Ε½ . O 1rn , improving on naive lower and upper bounds of 2 and 4, respectively.
π SIMILAR VOLUMES
## Abstract For simple graphs __G__ and __H__, let __f__(__G__,__H__) denote the least integer __N__ such that every coloring of the edges of __K__~__N__~ contains either a monochromatic copy of __G__ or a rainbow copy of __H__. Here we investigate __f__(__G__,__H__) when __H__β=β__P__~__k__~. We s
We ask, When does a graph G have a subgraph I' such that the vertices of odd degree in form a specified set S C V ( G ) , such that G -E(T) is connected? If such a subgraph can be found for a suitable choice of S, then this can be applied to problems such as finding a spanning eulerian subgraph of G
The MAXIMUM PLANAR SUBGRAPH problemαgiven a graph G, find a largest planar subgraph of Gαhas applications in circuit layout, facility layout, and graph drawing. No previous polynomial-time approximation algorithm for this NP-Complete problem was known to achieve a performance ratio larger than 1r3,