Java

  • import java.util.HashSet;
    import java.util.Set;
    
    /**
    
     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 "--...--.".
    
     */
    public class Unique_Morse_Code_Words {
        class Solution {
            public int uniqueMorseRepresentations(String[] words) {
                String[] MORSE = new String[]{
                    ".-","-...","-.-.","-..",".","..-.","--.",
                    "....","..",".---","-.-",".-..","--","-.",
                    "---",".--.","--.-",".-.","...","-","..-",
                    "...-",".--","-..-","-.--","--.."};
    
                Set<String> seen = new HashSet<>();
                for (String word: words) {
                    StringBuilder code = new StringBuilder();
                    for (char c: word.toCharArray())
                        code.append(MORSE[c - 'a']);
                    seen.add(code.toString());
                }
    
                return seen.size();
            }
        }
    }
    
  • // OJ: https://leetcode.com/problems/unique-morse-code-words/
    // Time: O(N)
    // Space: O(N)
    class Solution {
    private:
        string dict[26] = {".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."};
    public:
        int uniqueMorseRepresentations(vector<string>& words) {
            unordered_set<string> s;
            for (string word : words) {
                string code;
                for (char c : word) code += dict[c - 'a'];
                s.insert(code);
            }
            return s.size();
        }
    };
    
  • class Solution(object):
        def uniqueMorseRepresentations(self, words):
            """
            :type words: List[str]
            :rtype: int
            """
            moorse = [".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."]
            trans = lambda x: moorse[ord(x) - ord('a')]
            map_word = lambda word: ''.join([trans(x) for x in word])
            res = map(map_word, words)
            return len(set(res))
    

Java

  • class Solution {
        public int uniqueMorseRepresentations(String[] words) {
            String[] morseArray = {".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."};
            Set<String> set = new HashSet<String>();
            for (String word : words) {
                StringBuffer sb = new StringBuffer();
                char[] array = word.toCharArray();
                for (char c : array)
                    sb.append(morseArray[c - 'a']);
                set.add(sb.toString());
            }
            return set.size();
        }
    }
    
  • // OJ: https://leetcode.com/problems/unique-morse-code-words/
    // Time: O(N)
    // Space: O(N)
    class Solution {
    private:
        string dict[26] = {".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."};
    public:
        int uniqueMorseRepresentations(vector<string>& words) {
            unordered_set<string> s;
            for (string word : words) {
                string code;
                for (char c : word) code += dict[c - 'a'];
                s.insert(code);
            }
            return s.size();
        }
    };
    
  • class Solution(object):
        def uniqueMorseRepresentations(self, words):
            """
            :type words: List[str]
            :rtype: int
            """
            moorse = [".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."]
            trans = lambda x: moorse[ord(x) - ord('a')]
            map_word = lambda word: ''.join([trans(x) for x in word])
            res = map(map_word, words)
            return len(set(res))
    

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