Closest Nodes Queries in a Binary Search Tree

You are given the root of a binary search tree and an array queries of size n consisting of positive integers.

Find a 2D array answer of size n where answer[i] = [mini, maxi]:

mini is the largest value in the tree that is smaller than or equal to queries[i]. If such a value does not exist, use -1 instead.
maxi is the smallest value in the tree that is greater than or equal to queries[i]. If such a value does not exist, use -1 instead.

Return the array answer.

Example 1

        6
       / \
      2   13
     / \  / \
    1   4 9  15
              /
             14

Inputroot = [6,2,13,1,4,9,15,null,null,null,null,null,null,14], queries = [2,5,16]

Output[[2,2],[4,6],[15,-1]]

For the queries 2, 5, and 16, the closest lower and upper values are [2,2], [4,6], and [15,-1], respectively.

Example 2

    4
     \
      9

Inputroot = [4,null,9], queries = [3]

Output[[-1,4]]

The largest number smaller than or equal to 3 does not exist, and the smallest number greater than or equal to 3 is 4.

Constraints