Exercise · ZW-GRAPH-COLORING-004 · ★☆☆ Basic
What is the minimum number of colors needed by the cycle \(C_8\)?
Choose one option.
A 3 B 4 C 2 D 8
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Explanation In an even cycle the colors alternate and the pattern closes correctly: 2 colors suffice, and an edge already requires 2.
A proper coloring \(c\) with \(k\) colors of a graph \(G=(V,E)\) assigns to each vertex one of the colors \(1,\dots,k\) so that no two adjacent vertices share a color.
\[c:V\to\{1,\dots,k\},\qquad c(u)\neq c(v)\ \text{ if } \{u,v\}\in E\]
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