#95

Unique Binary Search Trees II

specialist · 685 · lc medium +30 · verified · 62% accepted · 7,938 likes · top 63%

Description

Given integer n, construct and return all structurally distinct BSTs that use each integer value from 1 to n exactly once. Results may be in any order.

Example 1:

Input: n = 3

Output: [[1,null,2,null,3],[1,null,3,2],[2,1,3],[3,1,null,null,2],[3,2,null,1]]

Example 2:

Input: n = 1

Output: [[1]]

Code

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def generateTrees(self, n: int) -> List[Optional[TreeNode]]:

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def generateTrees(self, n: int) -> List[Optional[TreeNode]]: