1.题目International Morse Code defines a standard encoding where each letter is mapped to a series of dots and dashes, as follows: “a” maps to “.-”, “b” maps to “-…”, “c” maps to “-.-.”, and so on.For convenience, the full table for the 26 letters of the English alphabet is given below:[".-","-…","-.-.","-..",".","..-.","–.","….","..",".—","-.-",".-..","–","-.","—",".–.","–.-",".-.","…","-","..-","…-",".–","-..-","-.–","–.."]Now, given a list of words, each word can be written as a concatenation of the Morse code of each letter. For example, “cba” can be written as “-.-..–…”, (which is the concatenation “-.-.” + “-…” + “.-”). We’ll call such a concatenation, the transformation of a word.Return the number of different transformations among all words we have.Example:Input: words = [“gin”, “zen”, “gig”, “msg”]Output: 2Explanation: The transformation of each word is:“gin” -> “–…-.““zen” -> “–…-.““gig” -> “–…–.““msg” -> “–…–.“There are 2 different transformations, “–…-.” and “–…–.".自己的解决方法class Solution: def uniqueMorseRepresentations(self, words: List[str]) -> int: final_set = set() mosLIst = [”.-”,”-…”,”-.-.”,”-..”,”.","..-.","–.","….","..",".—","-.-",".-..","–","-.","—",".–.","–.-",".-.","…","-","..-","…-",".–","-..-","-.–","–.."] for word in words: temp = ’’ for i in word: temp += mosLIst[ord(i)-97] final_set.add(temp) return len(final_set)Runtime: 36 ms, faster than 97.45% of Python3 online submissions for Unique Morse Code Words.Memory Usage: 12.9 MB, less than 5.36% of Python3 online submissions for Unique Morse Code Words.3.其他解决方法const codes = [".-","-…","-.-.","-..",".","..-.","–.","….","..",".—","-.-",".-..","–","-.","—",".–.","–.-",".-.","…","-","..-","…-",".–","-..-","-.–","–.."]const getIdx = char => char.charCodeAt(0) - ‘a’.charCodeAt(0)var uniqueMorseRepresentations = function(words) { return words.map( word => word.split(’’) .map( char => codes[getIdx(char)]) .join(’’)) .reduce((set, cur) => set.add(cur), new Set()) .size};