Unique Binary Tree is possible when, post-order/pre-order AND in-order traversals are given.
Unique Full Binary Tree is possible when, post-order AND pre-order traversals are given.
Unique Complete Binary Tree is possible when any ONE i.e, in-order or post-order or pre-order is given.
Therefore, for a Binary Tree, it is not possible to construct it uniquely when in-order isn’t given along with post-order/pre-order.