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 most 100.
Each words[i] will have length in range [1, 12].
words[i] will only consist of lowercase letters.

给定了26字母的摩斯电码的编码，给一组单词，把每个单词都转成摩斯码，返回有多少个不同的摩斯码。

解法：题目很简单，直接转换判断即可。

Java:

public int uniqueMorseRepresentations(String[] words) {

        String[] d = {".-", "-...", "-.-.", "-..", ".", "..-.", "--.", "....", "..", ".---", "-.-", ".-..", "--", "-.", "---", ".--.", "--.-", ".-.", "...", "-", "..-", "...-", ".--", "-..-", "-.--", "--.."};

        HashSet<String> s = new HashSet<>();

        for (String word : words) {

            String code = "";

            for (char c : word.toCharArray()) code += d[c - 'a'];

            s.add(code);

        }

        return s.size();

    }

Python:

def uniqueMorseRepresentations(self, words):

        d = [".-", "-...", "-.-.", "-..", ".", "..-.", "--.", "....", "..", ".---", "-.-", ".-..", "--",

             "-.", "---", ".--.", "--.-", ".-.", "...", "-", "..-", "...-", ".--", "-..-", "-.--", "--.."]

        return len({''.join(d[ord(i) - ord('a')] for i in w) for w in words})

Python:

# Time:  O(n), n is the sume of all word lengths

# Space: O(n)

class Solution(object):

    def uniqueMorseRepresentations(self, words):

        """

        :type words: List[str]

        :rtype: int

        """

        MORSE = [".-", "-...", "-.-.", "-..", ".", "..-.", "--.",

                 "....", "..", ".---", "-.-", ".-..", "--", "-.",

                 "---", ".--.", "--.-", ".-.", "...", "-", "..-",

                 "...-", ".--", "-..-", "-.--", "--.."]

        lookup = {"".join(MORSE[ord(c) - ord('a')] for c in word) \

                  for word in words}

        return len(lookup)

Python: wo

class Solution(object):

    def uniqueMorseRepresentations(self, words):

        """

        :type words: List[str]

        :rtype: int

        """

        m = [".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."]

        trans = []

        res = 0

        for word in words:

            temp = ''

            for c in word:

                temp += m[ord(c) - 97]

            if temp not in trans:

                trans.append(temp)

                res += 1

        return res

C++:

int uniqueMorseRepresentations(vector<string>& words) {

        vector<string> d = {".-", "-...", "-.-.", "-..", ".", "..-.", "--.", "....", "..", ".---", "-.-", ".-..", "--", "-.", "---", ".--.", "--.-", ".-.", "...", "-", "..-", "...-", ".--", "-..-", "-.--", "--.."};

        unordered_set<string> s;

        for (auto word : words) {

            string code;

            for (auto c : word) code += d[c - 'a'];

            s.insert(code);

        }

        return s.size();

    }

C++:

class Solution {

public:

    int uniqueMorseRepresentations(vector<string>& words) {

        vector<string> morse{".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."};

        unordered_set<string> s;

        for (string word : words) {

            string t = "";

            for (char c : word) t += morse[c - 'a'];

            s.insert(t);

        }

        return s.size();

    }

};

假定followup: 给一个单词的摩斯码，问有几种可能的单词，比如："--...-."，至少有两种zen和gin

All LeetCode Questions List 题目汇总

巴特西

[LeetCode] 804. Unique Morse Code Words 独特的摩斯码单词

All LeetCode Questions List 题目汇总

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