My first instinct was DFS and that was the right call, but I fumbled around for a bit before nailing down the base cases.
Clarify the problem constraints and edge cases, then propose a recursive DFS solution that traverses the tree while matching the sequence. Explain the algorithm step-by-step, analyze time and space complexity, and write clean code with proper handling of base cases.
Pro tip: Emphasize early termination and pruning: if the current node's value doesn't match the sequence at the current index, backtrack immediately. This shows optimization mindset and can significantly reduce runtime in practice.
Ask clarifying questions about input constraints, such as tree size, sequence length, and whether the sequence can be empty. Confirm that the path must start at the root and can end at any node.
Propose a recursive DFS approach: at each node, check if its value matches the current sequence element, then recurse on children with the next index. If the sequence is fully matched, return true.
State that time complexity is O(N) in the worst case, where N is the number of nodes, as each node is visited at most once. Space complexity is O(H) for recursion stack, where H is the tree height.
Implement the recursive function with clear base cases: if index equals sequence length, return true; if node is null or value mismatch, return false. Iterate through children and return true if any path matches.
Walk through examples including empty sequence, single node, repeated values, and deep trees. Mention potential optimizations like iterative DFS to avoid recursion limits.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.