_804.java

package com.fishercoder.solutions;

import java.util.HashSet;
import java.util.Set;

/**
 * 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, "cab" 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: 2
 Explanation:
 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.
 */
public class _804 {
  public static class Solution1 {
    public int uniqueMorseRepresentations(String[] words) {
      String[] morseCodes =
          new String[] {".-", "-...", "-.-.", "-..", ".", "..-.", "--.", "....", "..", ".---",
              "-.-", ".-..", "--", "-.", "---", ".--.", "--.-", ".-.", "...", "-", "..-", "...-",
              ".--", "-..-", "-.--", "--.."};
      Set<String> concatenation = new HashSet<>();
      StringBuilder sb = new StringBuilder();
      for (String word : words) {
        sb.setLength(0);
        for (char c : word.toCharArray()) {
          sb.append(morseCodes[c - 'a']);
        }
        concatenation.add(sb.toString());
      }
      return concatenation.size();
    }
  }
}