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 "--...--.".
Note:
- The length of
words
will be at most100
. - Each
words[i]
will have length in range[1, 12]
. words[i]
will only consist of lowercase letters.
Code (Java):
class Solution { public int uniqueMorseRepresentations(String[] words) { if (words == null || words.length == 0) { return 0; } Set<String> morseCodeSet = new HashSet<>(); int ans = 0; for (String word : words) { String morseCode = GetMorseCode(word); if (!morseCodeSet.contains(morseCode)) { morseCodeSet.add(morseCode); } } return morseCodeSet.size(); } private String GetMorseCode(String word) { String[] morseCodeDict = {".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."}; String morseCode = ""; for (int i = 0; i < word.length(); i++) { char c = word.charAt(i); morseCode += morseCodeDict[c - 'a']; } return morseCode; } }
why have we done charcater at [C-a]
ReplyDeleteto get the indexing from 0 C value can be from 97-122 so subtracting the value 97 will bring the index down to 0 for a , 1 for b and so on.
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