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A binary tree is uni-valued if every node in the tree has the same value.

Given the root of a binary tree, return true if the given tree is uni-valued, or false otherwise.

Example 1:

Input: root = [1,1,1,1,1,null,1]
Output: true

Example 2:

Input: root = [2,2,2,5,2]
Output: false

Constraints:

• The number of nodes in the tree is in the range [1, 100].
• 0 <= Node.val < 100

[Tree] [Depth-First Search] [Breadth-First Search] [Binary Tree]

1. Find All The Lonely Nodes (Easy)