Bipartite subgraphs of graphs with maximum degree three

被引:7
作者
Bylka, SA [1 ]
Idzik, A [1 ]
Komar, J [1 ]
机构
[1] Polish Acad Sci, Inst Comp Sci, PL-02137 Warsaw, Poland
关键词
bipartite graph; n-colourable graph; extremal graph;
D O I
10.1007/s003730050047
中图分类号
O1 [数学];
学科分类号
0701 ; 070101 ;
摘要
We prove that for a connected graph G with maximum degree 3 there exists a bipartite subgraph of G containing almost 3/4 of the edges of G. Furthermore, we completely characterize the set of all extremal graphs, i.e. all connected graphs G = (V, E) with maximum degree 3 for which no bipartite subgraph has more than 3 \E\ - 1/4 of the edges; \E\ denotes the cardinality of E. For 2-edge-connected graphs there are two kinds of extremal graphs which realize the lower bound 3/4 \E\.
引用
收藏
页码:129 / 136
页数:8
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