leetcode-804-easy

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.

思路一：先转换，然后用 set 记录

    public int uniqueMorseRepresentations(String[] words) {
        String[] data = new String[]{".-", "-...", "-.-.", "-..", ".", "..-.", "--.", "....", "..", ".---", "-.-", ".-..", "--", "-.", "---", ".--.", "--.-", ".-.", "...", "-", "..-", "...-", ".--", "-..-", "-.--", "--.."};
        Set<String> set = new HashSet<>();

        for (int i = 0; i < words.length; i++) {
            StringBuilder sb = new StringBuilder();
            for (int j = 0; j < words[i].length(); j++) {
                sb.append(data[words[i].charAt(j) - 'a']);
            }

            set.add(sb.toString());
        }

        return set.size();
    }