leetcode/804.unique_morse_code_words.js at master · Matthew-SA/leetcode · GitHub

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// 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: 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.


var uniqueMorseRepresentations = function(words) {
  let morseWords = {};
  let count = 0;

  let alpha = {
      "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": "--.."
  }

  for (let word of words) {
    let morseWord = '';
    for (let char of word) {
      morseWord += alpha[char];
    }
    if (morseWords[morseWord] === undefined) {
      morseWords[morseWord] = true;
      count += 1;
    }
  }
  return count;
};