My first instinct was BFS and I started going down that road before catching myself.
Use a recursive divide-and-conquer strategy: compute the height of the tree to determine the matrix dimensions (rows = height, columns = 2^height - 1). Then, recursively place each node at the correct column based on its position in the inorder traversal, filling empty spaces with empty strings.
Pro tip: Clarify the exact formatting rules (e.g., whether to use empty strings or spaces for missing nodes) and discuss trade-offs between recursive and iterative approaches, showing awareness of potential stack overflow for deep trees.
Confirm the rules for matrix dimensions and node placement. Ask clarifying questions about edge cases like empty tree or single node.
Calculate the height of the tree (number of levels) to determine rows = height and columns = 2^height - 1.
Perform an inorder traversal to assign each node a column index (0-based) in the matrix, ensuring correct horizontal placement.
Recursively place each node's value at its row (level) and assigned column, filling other cells with empty strings.
Discuss time and space complexity (O(n) time, O(n) space for matrix) and handle edge cases like empty tree.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.