What is the chromatic number of an $n$ vertex simple connected graph which does not contain any odd length cycle? Assume $n > 2$.

(A) 2

(B) 3

(C) n-1

(D) n

Solution by Happy Mittal

Chromatic number of a graph is the minimum number of colors required to color all vertices such that no two adjacent vertices are colored with same color. Since here we have no odd cycle, we can color whole graph with only $2$ colors, coloring the vertices with alternate colors. So option (A) is correct.




blog comments powered by Disqus

What is the chromatic number of an $n$ vertex simple connected graph which does not contain any odd length cycle? Assume $n > 2$.

(A) 2

(B) 3

(C) n-1

(D) n

Solution by Happy Mittal[edit]

Chromatic number of a graph is the minimum number of colors required to color all vertices such that no two adjacent vertices are colored with same color. Since here we have no odd cycle, we can color whole graph with only $2$ colors, coloring the vertices with alternate colors. So option (A) is correct.




blog comments powered by Disqus