Unique Binary Search Trees
Oct 31, 2021
--
Given an integer n
, return the number of structurally unique BST's (binary search trees) which has exactly n
nodes of unique values from 1
to n
.
Example 1:
Input: n = 3
Output: 5
Example 2:
Input: n = 1
Output: 1
Constraints:
1 <= n <= 19