Clarify the problem constraints (e.g., dictionary size, string length, whether words can be reused) and then propose a recursive backtracking solution that tries all possible word breaks. Optimize with memoization to avoid recomputing overlapping subproblems, and analyze time/space complexity.
Pro tip: Mention that this is essentially the 'Word Break II' problem and that you would use memoization to cache results for each starting index, which drastically reduces redundant work. Also, discuss how you would handle large inputs by considering pruning or using a trie for the dictionary.
Ask about input sizes, dictionary characteristics (e.g., case sensitivity, duplicates), and expected output format. Confirm whether the same word can be used multiple times and if the entire string must be segmented.
Explain that you will recursively try every possible prefix of the remaining string; if the prefix is in the dictionary, recurse on the remainder and combine the prefix with the results from the remainder.
Use a hash map to store results for each starting index to avoid recomputing the same subproblem. This reduces time complexity from exponential to polynomial in many cases.
Discuss time and space complexity, considering the number of valid sentences and the length of the string. Mention edge cases like empty string, no valid segmentation, and very long strings.
Mention using a trie for the dictionary to speed up prefix lookups, or pruning branches early if no word can start at a certain position. Also, consider iterative DP if only the existence of a segmentation is needed.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.