(a) Assume that you are given both the preorder and post order traversal of some binary tree t. Prove that this information, taken together, is not necessarily sufficient to reconstruct t uniquely, even if each value in t occurs only once.

(b) Now, assume that you have the preorder and in order traversals of a tree (given below). Construct the corresponding binary tree and determine its post order traversal.

• Preorder Traversal: D C B A F E

• In order Traversal: C A B D E F