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Yes, variations of this problem appear in interviews at companies like Google, Amazon, and Meta. It tests understanding of DFS on trees, dynamic state propagation, and how to combine results from multiple subtrees.
Unlike simpler consecutive sequence problems, the valid path here can go up and then down (or vice versa). Tracking both increasing and decreasing sequences lets us merge them at a node to form the longest valid path.
A binary tree with recursive DFS traversal is the most suitable structure for solving this problem. The recursion allows you to propagate increasing and decreasing sequence lengths from children to parents while evaluating possible combined paths.
The optimal approach uses Depth-First Search while tracking two values for each node: the longest increasing and decreasing consecutive sequences. By combining these values at every node, we can compute paths that pass through the node and update the global maximum efficiently.