Count Good Nodes in Binary Tree

Input: root = [3,1,4,3,null,1,5]

Output: 4

Root node (3) is always good. Node 4 -> path (3,4) has max 4. Node 5 -> path (3,4,5) has max 5. Node 3 -> path (3,1,3) has max 3. These 4 nodes are good.

Input: root = [3,3,null,4,2]

Output: 3

Node 2 -> path (3,3,2) is not good because 3 is greater than 2.

Input: root = [1]

Output: 1

The root is always considered good.

Count Good Nodes in Binary Tree

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