Term Test 2 ( Week 10)

This week, we do not have any lectures due to Fall break and Term test2. So I just want to spend some time to conclude our Term test2. The questions were entirely based on binary trees and binary search trees. There were three questions in total. First question needed us to count interior nodes and the number of leaves. I just wrote two helper function, one was count_interior and the other was count_leaves, return (count_interior, count_leaves).

Second question needed us to return number of nodes with value that is an even int. I wrote such long codes. But professor only wrote in a line, which was return

(count_even(n.left) + count_even(n.right) + (1 if n.value % 2 == 0 else 0) if n else 0)

That’s amazing! The most excited was the third question. We needed to build a linked list of the path from root to minimum element and return the first node in the linked list. For example,

>>> min_path(BSTNode(4, BSTNode(3, None, None), BSTNode(5, None, None)))

LLNode(4, LLNode(3, None))

I had no idea. However, our professor gave us only a line as well.

return LLNode(n.value, min_path(n.left)) if n else None

That let me learn so much! I need more time to understand them.