Given the root of a binary search tree, return a balanced binary search tree with the same node values. If there is more than one answer, return any of them.
A binary search tree is balanced if the depth of the two subtrees of every node never differs by more than 1.
Example 1:
Input: root = [1,null,2,null,3,null,4,null,null] Output: [2,1,3,null,null,null,4] Explanation: This is not the only correct answer, [3,1,4,null,2] is also correct.
Example 2:
Input: root = [2,1,3] Output: [2,1,3]
Constraints:
- The number of nodes in the tree is in the range
[1, 104]. 1 <= Node.val <= 105
[Divide and Conquer] [Greedy] [Tree] [Depth-First Search] [Binary Search Tree] [Binary Tree]