Medium

Quiz

#96 Unique Binary Search Trees

APPROACH

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

1 of 4

What is the optimal approach for this problem?