- Description
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 “–…–.”.
- Solution
private static String[] morseCode = { ".-", "-...", "-.-.", "-..", ".", "..-.", "--.", "....", "..", ".---", "-.-",
".-..", "--", "-.", "---", ".--.", "--.-", ".-.", "...", "-", "..-", "...-", ".--", "-..-", "-.--",
"--.." };
public static int uniqueMorseCodeWords(String[] words) {
int slength = words.length;
int uniqueWords = 0;
HashMap<Integer, String> sMorseCode = new HashMap<>();
for (int i = 0; i < slength; i++) {
int clength = words[i].length();
StringBuilder mValue = new StringBuilder();
for (int j = 0; j < clength; j++) {
char s = words[i].charAt(j);
int sindex = s - 'a';
String letterMorse = morseCode[sindex];
mValue = mValue.append(letterMorse);
}
if (!sMorseCode.containsValue(mValue.toString())) {
uniqueWords++;
}
sMorseCode.put(i, mValue.toString());
}
System.out.println("unique morse code word : " + uniqueWords);
return uniqueWords;
}