pre_order(L): creates a binary search tree from a LlST of preordered k,v tupIes, the input should be a list and the output should be the binary search tree

post_order(L): creates a binary search tree from a LlST of post order k,v tupIes, the input should be a list and the output should be the binary search tree

 

3: '3' / 1: '1' # # / # 0:'0' 2: '2' Traversals of this tree yields the following lists of k:v tuples: pre-order: [(3, '3'), (1,'1'), (0, '0'), (2, '2')] post-order: [(0, '0'), (2, '2'), (1,'1'), (3, '3')].