  Bidirectional quantum teleportation scheme is a two-way quantum communication
process, in which two parties simultaneously receive each other information.
Recently, in paper [1] (Zhou et al., IEEE Access, 7, 44269 (2019)), a six-qubit
cluster state has been used to teleport three-qubit entangled state (Alice) and
arbitrary single-qubit unknown quantum state (Bob) bidirectionally. An
experimental point of view, the preparation and the maintenance of cluster type
entangled state is very difficult and costly. So, in this paper we have
designed an optimal scheme for bidirectional quantum teleportation scheme and
shown that proposed scheme requires optimized amount of quantum resources.
