Definition:Path Graph

Definition
A path graph is a tree which has a path which passes through all its vertices.

The path graph with $n$ vertices is denoted $P_n$.

Examples

 * PathGraphs.png

Basic Properties

 * $P_1$ is the edgeless graph $N_1$, and also the complete graph $K_1$.


 * $P_1$ is (trivially) Hamiltonian and Eulerian.


 * $P_2$ is the complete bipartite graph $K_{1, 1}$, and is $1$-regular.


 * $P_3$ is the complete bipartite graph $K_{1, 2}$.


 * $P_n$ is semi-Hamiltonian and semi-Eulerian for all $n \ge 2$.