# Leetcode 543 - Diameter of binary tree

Note:

• It doesn’t feel like an easy question.
• Idea: Iterate each node and add its leftDepth with rightDepth while comparing with result.
• Detail:
• If left and right subtree both exist, leftDepth + rightDepth + 1 + 1.
• But if one of them doesn’t exist, we need to check we add 1 or 0, like node.left ? 1 : 0.

Given the root of a binary tree, return the length of the diameter of the tree.

The diameter of a binary tree is the length of the longest path between any two nodes in a tree. This path may or may not pass through the root.

The length of a path between two nodes is represented by the number of edges between them.

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