Let's say a Markov chain has the state-space $S = \{A,B,C,D\}$ Transition Matrix as follows:
$ \begin{bmatrix} 0 & 0 & 0 & 1 \\ 1 & 0 & 0 & 0 \\ 0 & 0 & 0 & 1 \\ 0 & 1 & 0 & 0 \end{bmatrix} $
This is NOT irreducible as far as I am aware due to state C being transient.
To find an equilibrium distribution for the chain, would I just treat it the same way as if it were irreducible in which case I get $\pi = (1/3)(1,1,0,1)$. Is this unique? I'm not sure. Thanks in advance!