804. Unique Morse Code Words

string

https://leetcode.com/problems/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:

[".-","-…","-.-.","-..",".","..-.","–.","….","..",".—","-.-",".-..","–","-.","—",".–.","–.-",".-.","…","-","..-","…-",".–","-..-","-.–","–.."] Given an array of strings words where each word can be written as a concatenation of the Morse code of each letter.

For example, "cab" can be written as "-.-..--...", which is the concatenation of "-.-.", ".-", and "-...". We will call such a concatenation the **transformation** of a word.Return __the number of different **transformations** among all words we have__.

Example 1: Input: words = [“gin”,“zen”,“gig”,“msg”] Output: 2 Explanation: The transformation of each word is: “gin” -> “–…-.” “zen” -> “–…-.” “gig” -> “–…–.” “msg” -> “–…–.” There are 2 different transformations: “–…-.” and “–…–.”. Example 2: Input: words = [“a”] Output: 1

Constraints:

1 <= words.length <= 100 	
1 <= words[i].length <= 12 	
words[i] consists of lowercase English letters.
  • code
class Solution {
    public int uniqueMorseRepresentations(String[] words) {
        String[] m = {".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."};
        Set<String> s = new HashSet<>();
        
        for (String word: words){
            StringBuilder sb = new StringBuilder();
            for (char c: word.toCharArray()){
                sb.append(m[c - 'a']);
            }
            s.add(sb.toString());
        }
        return s.size();
    }
}