804. Unique Morse Code Words LeetCode Solution

In this guide, you will get 804. Unique Morse Code Words LeetCode Solution with the best time and space complexity. The solution to Unique Morse Code Words problem is provided in various programming languages like C++, Java, and Python. This will be helpful for you if you are preparing for placements, hackathons, interviews, or practice purposes. The solutions provided here are very easy to follow and include detailed explanations.

Problem Statement
Complexity Analysis
Unique Morse Code Words solution in C++
Unique Morse Code Words solution in Java
Unique Morse Code Words solution in Python
Additional Resources

804. Unique Morse Code Words LeetCode Solution image

Problem Statement of 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.

Complexity Analysis

Time Complexity: O(\Sigma |\texttt{words[i]}|)
Space Complexity: O(|\texttt{words}|)

804. Unique Morse Code Words LeetCode Solution in C++

class Solution {
 public:
  int uniqueMorseRepresentations(vector<string>& words) {
    const vector<string> morse{
        ".-",   "-...", "-.-.", "-..",  ".",   "..-.", "--.",  "....", "..",
        ".---", "-.-",  ".-..", "--",   "-.",  "---",  ".--.", "--.-", ".-.",
        "...",  "-",    "..-",  "...-", ".--", "-..-", "-.--", "--.."};
    unordered_set<string> transformations;

    for (const string& word : words) {
      string transformation;
      for (const char c : word)
        transformation += morse[c - 'a'];
      transformations.insert(transformation);
    }

    return transformations.size();
  }
};
/* code provided by PROGIEZ */

804. Unique Morse Code Words LeetCode Solution in Java

class Solution {
  public int uniqueMorseRepresentations(String[] words) {
    final String[] morse = {".-",   "-...", "-.-.", "-..",  ".",   "..-.", "--.",  "....", "..",
                            ".---", "-.-",  ".-..", "--",   "-.",  "---",  ".--.", "--.-", ".-.",
                            "...",  "-",    "..-",  "...-", ".--", "-..-", "-.--", "--.."};
    Set<String> transformations = new HashSet<>();

    for (final String word : words) {
      StringBuilder transformation = new StringBuilder();
      for (final char c : word.toCharArray())
        transformation.append(morse[c - 'a']);
      transformations.add(transformation.toString());
    }

    return transformations.size();
  }
}
// code provided by PROGIEZ

804. Unique Morse Code Words LeetCode Solution in Python

class Solution:
  def uniqueMorseRepresentations(self, words: list[str]) -> int:
    morse = [".-", "-...", "-.-.", "-..", ".", "..-.", "--.", "....", "..",
             ".---", "-.-", ".-..", "--", "-.", "---", ".--.", "--.-", ".-.",
             "...", "-", "..-", "...-", ".--", "-..-", "-.--", "--.."]
    transformations = set()

    for word in words:
      transformation = ''.join(
          morse[string.ascii_lowercase.index(c)] for c in word)
      transformations.add(transformation)

    return len(transformations)
 # code by PROGIEZ