推 nendi :居然被秒殺了,大大真是太厲害了,感謝這位大大幫忙^ 03/14 10:05
※ 引述《nendi (midi)》之銘言:
: 1.Let G be a graph with mk edges.
: Prove that if G is k-edge colorable, then there is a k-edge coloring f of G
: in which every color class contains exactly m edges.
Let C_1,..,C_k be the color classes.
If |C_i|>|C_j|, consider C_i\cup C_j, there is a path P s.t.
|E(P)\cap C_i|=|E(P)\cap C_j|+1. Then we exchange the two colors on E(P) and
the following can be done by induction.
: 2.Prove that if a cubic graph G has a hamilton cycle,
: then G is 3-edge colorable.
cubic => n(G) is even
We can color the edges of the Hamiltonian cycle C by two colors, and color
E(G)-E(C) by another color.
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