2022-08-17 Daily-Challenge

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Today I have done leetcode's August LeetCoding Challenge with cpp.

August LeetCoding Challenge 17

Description

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.

Solution

class Solution {
  vector<string> m{".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."};
public:
  int uniqueMorseRepresentations(vector<string>& words) {
    unordered_set<string> answer;
    for(auto &word : words) {
      string code = "";
      for(auto c : word) {
        code += m[c-'a'];
      }
      answer.insert(code);
    }
    return answer.size();
  }
};

// Accepted
// 82/82 cases passed (4 ms)
// Your runtime beats 71.25 % of cpp submissions
// Your memory usage beats 61.19 % of cpp submissions (8.5 MB)
Algorithm