Structurally distinct BSTs
Given an integer n, return the number of structurally distinct binary search trees that store the values 1..n exactly once. n is between 0 and 19. (For n=0 there is one tree: the empty tree.)
Implement
num_trees(n: int) → intExamples
in
[3]out5What a strong answer looks like
State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.
0:00 of about 20 min
solution.py
InputExpectedGot
[3]5not run yetsample