Planar graphs without cycles of length 4 or 9 are $\boldsymbol{(2,~0,~0)}$-colorable
نویسندگان
چکیده
منابع مشابه
Planar graphs without cycles of length from 4 to 7 are 3-colorable
Planar graphs without cycles of length from 4 to 7 are proved to be 3-colorable. Moreover, it is proved that each proper 3-coloring of a face of length from 8 to 11 in a connected plane graph without cycles of length from 4 to 7 can be extended to a proper 3-coloring of the whole graph. This improves on the previous results on a long standing conjecture of Steinberg. © 2004 Elsevier Inc. All ri...
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Let G be a graph. It was proved that if G is a planar graph without {4, 6, 7}-cycles and without two 5-cycles sharing exactly one edge, then G 3-colorable. We observed that the proof of this result is not correct. 1 Let G be a simple graph with vertex set G. A planar graph is one that can be drawn on a plane in such a way that there are no “edge crossings,” i.e. edges intersect only at their co...
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ژورنال
عنوان ژورنال: SCIENTIA SINICA Mathematica
سال: 2019
ISSN: 1674-7216
DOI: 10.1360/n012018-00129