Threw the words into a set after mapping each character to its Morse equivalent and concatenating.
Start by clarifying the problem and edge cases, then propose a solution using a hash set to store unique Morse code strings. For each word, convert it to Morse by mapping each letter via a lookup table, and add the result to the set. Finally, return the set's size.
Pro tip: Mention that the Morse code mapping can be stored in an array of 26 strings for O(1) lookup, and emphasize that the time complexity is O(N*L) where N is the number of words and L is the average word length, which is optimal.
Ask about input constraints (e.g., word length, number of words, character set) and confirm that only lowercase English letters are used. Discuss handling of empty input or empty strings.
Propose using a set to track distinct Morse representations. For each word, build its Morse string by concatenating the code for each character, then insert into the set.
Use a precomputed array or hash map for Morse code lookup to ensure O(1) access per character. Iterate through each word and each character, appending to a StringBuilder for efficiency.
State that time complexity is O(N * L) where N is number of words and L is average length, and space complexity is O(N * L) in the worst case for storing distinct strings.
Walk through a small example, such as ['gin', 'zen'], to demonstrate that both map to the same Morse code and the set size is 1. Also test edge cases like empty array or single word.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.