This work was supported partially by the National Natural Science Foundation of China (Grant No.10471131);the Natural Science Foundation of Zhejiang Province(Grant No.Y604167)
In this paper we prove that every planar graph without 4,6 and 8-cycles is 3-colorable.
This work was partially supported by the National Natural Science Foundation of China (Grant No. 10471131)
Let G be a simple graph with maximum degree Δ(G) and total chromatic number x ve (G). Vizing conjectured that Δ(G) + 1 ? X ve (G) ? δ(G) + 2 (Total Chromatic Conjecture). Even for planar graphs, this conjecture has...