[Tree] [Recursion] - 938

Given the root node of a binary search tree, return the sum of values of all nodes with value between L and R (inclusive).

The binary search tree is guaranteed to have unique values.

 

Example 1:

Input: root = [10,5,15,3,7,null,18], L = 7, R = 15 Output: 32

Example 2:

Input: root = [10,5,15,3,7,13,18,1,null,6], L = 6, R = 10 Output: 23

 

Note:

1. The number of nodes in the tree is at most 10000.
2. The final answer is guaranteed to be less than 2^31.

 

 

 

 이미 정리가 되어있으므로 (Sorting)

 

O(logn)이다.