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95.Unique Binary Search Trees II

tags: Medium,DP,Tree,Backtracking

95. Unique Binary Search Trees II

題目描述

Given an integer n, return all the structurally unique BST's (binary search trees), which has exactly n nodes of unique values from 1 to n. Return the answer in any order.

範例

Example 1:

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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]]

Constraints:

  • 1 <= n <= 8

解答

Reference

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