804. Unique Morse Code Words

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 "--...--.".

Note:

• The length of words will be at most 100.
• Each words[i] will have length in range [1, 12].
• words[i] will only consist of lowercase letters.

题目描述：我们可以将单词描述为摩斯密码，问在一组单词中有多少个代表的莫斯密码是不同的。

题目分析：和 很类似，也是为了过滤掉重复的元素，我们可以用set集合去过滤。然后把单词转换为莫斯密码，然后过滤即可。

python 代码：

class Solution(object):    def uniqueMorseRepresentations(self, words):        """        :type words: List[str]        :rtype: int        """        maps = [".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."]        words_length = len(words)        morse_code = set()        for i in range(words_length):            word_string = words[i]            word_string_length = len(word_string)            string_code = ''            for i in range(word_string_length):                string_code += maps[ord(word_string[i]) - 97]            morse_code.add(string_code)                    return len(morse_code)

C++ 代码：

class Solution {public:    int uniqueMorseRepresentations(vector
    
     & words) {        set
     
       morse_code;        vector
      
        string_code(words.size());        vector
       
         maps = {".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."};//  a b c d e f g h i j  k  l  m  n  o  p  q  r  s  t  u  v  w  x  y  z//  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26        for(int i = 0; i < words.size(); i++){            for(int j = 0; j < words[i].size(); j++){                string_code[i].append(maps[words[i][j] - 'a']);            }        }        for(int i = 0; i < string_code.size(); i++){            morse_code.insert(string_code[i]);        }        return morse_code.size();    }};