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$ curl repovive.com/roadmaps/meta-interview-prep-v2/coding-patterns-ii-trees-graphs-advanced/lc-543-diameter-of-binary-tree-implementation

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$ curl repovive.com/roadmaps/meta-interview-prep-v2/coding-patterns-ii-trees-graphs-advanced/lc-543-diameter-of-binary-tree-implementation

Repovive

LeetCode 543 Diameter of Binary Tree - Implementation - Coding Patterns II: Trees, Graphs & Advanced | Meta Interview Prep | Repovive

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Meta Interview Prep6 sections · 147 units8h total

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LeetCode 543 Diameter of Binary Tree - Implementation

The code

Run DFS to compute depth at each node. Track the maximum of leftDepth + rightDepth across all nodes.

Here's the solution:

function diameterOfBinaryTree(root):
    maxDiameter = 0

    function depth(node):
        if node is null:
            return 0
        left = depth(node.left)
        right = depth(node.right)
        maxDiameter = max(maxDiameter, left + right)
        return 1 + max(left, right)

    depth(root)
    return maxDiameter

$O(n)$ time, $O(h)$ space where $h$ is the tree height.