Unique Binary Search Trees
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 = 3Output
5There are 5 structurally unique BSTs that can store the values 1, 2, and 3.
Example 2
Input
n = 1Output
1With only one value, there is exactly one possible BST.
Constraints
- 1 <= n <= 19