STAR COLOURING IN FEW CLASSES OF GRAPHS

A proper vertex colouring of a graph $G$ is called a star colouring if every path of $G$ on four vertices is not 2-coloured. The star chromatic number is the minimum number of colours required to star colour $G$ and it is denoted by $\chi_s(G)$. The Star Chromatic Number of the Middle Graphs of path $(P_n)$; Shadow Graphs of path $(P_n)$ and Tadpole graphs $(T_{3,n})$; $m$- fold Triangular Snake graphs $(S(C_3,m,n))$ have been discussed in this paper.