2265 - Count Nodes Equal to Average of Subtree.

Medium

Given the root of a binary tree, return the number of nodes where the value of the node is equal to the average of the values in its subtree.

Note:

• The average of n elements is the sum of the n elements divided by n and rounded down to the nearest integer.

• A subtree of root is a tree consisting of root and all of its descendants.

Example 1:

Input: root = 4,8,5,0,1,null,6

Output: 5

Explanation:

For the node with value 4: The average of its subtree is (4 + 8 + 5 + 0 + 1 + 6) / 6 = 24 / 6 = 4.

For the node with value 5: The average of its subtree is (5 + 6) / 2 = 11 / 2 = 5.

For the node with value 0: The average of its subtree is 0 / 1 = 0.

For the node with value 1: The average of its subtree is 1 / 1 = 1.

For the node with value 6: The average of its subtree is 6 / 1 = 6.

Example 2:

Input: root = 1

Output: 1

Explanation: For the node with value 1: The average of its subtree is 1 / 1 = 1.

Constraints:

• The number of nodes in the tree is in the range [1, 1000].

• 0 <= Node.val <= 1000