1602. Find Nearest Right Node in Binary Tree

https://leetcode.com/problems/find-nearest-right-node-in-binary-tree

Description

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.

• u is a node in the binary tree rooted at root.

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