Given the root of a binary tree and a node u in the tree, return the nearest node on the same level that is to the right of u, or return null if u is the rightmost node in its level.
Example 1:
Input: root = [1,2,3,null,4,5,6], u = 4 Output: 5 Explanation: The nearest node on the same level to the right of node 4 is node 5.
Example 2:
Input: root = [3,null,4,2], u = 2 Output: null Explanation: There are no nodes to the right of 2.
Example 3:
Input: root = [1], u = 1 Output: null
Example 4:
Input: root = [3,4,2,null,null,null,1], u = 4 Output: 2
Constraints:
- The number of nodes in the tree is in the range
[1, 105]. 1 <= Node.val <= 105- All values in the tree are distinct.
uis a node in the binary tree rooted atroot.