was it a binary tree or a binary search tree? a BST can be uniquely identified by one of pre/post-order traversal, whereas a binary tree requires an in-order tr

was it a binary tree or a binary search tree? a BST can be uniquely identified by one of pre/post-order traversal, whereas a binary tree requires an in-order traversal and one other. or placing sentinels that specify a state machine [PUSH_LEFT, PUSH_RIGHT, POP] that specify how to move down and up the tree structure.