New Solution "Unique Morse Code Words"

README.md

@@ -11,6 +11,7 @@ LeetCode
 |859|[Buddy Strings](https://leetcode.com/problems/buddy-strings/description/) | [C++](./algorithms/cpp/buddyStrings/BuddyStrings.cpp)|Easy|
 |858|[Mirror Reflection](https://leetcode.com/problems/mirror-reflection/description/) | [C++](./algorithms/cpp/mirrorReflection/MirrorReflection.cpp)|Medium|
 |837|[Most Common Word](https://leetcode.com/problems/most-common-word/) | [C++](./algorithms/cpp/mostCommonWord/MostCommonWord.cpp)|Easy|
+|804|[Unique Morse Code Words](https://leetcode.com/problems/unique-morse-code-words/description/) | [C++](./algorithms/cpp/uniqueMorseCodeWords/UniqueMorseCodeWords.cpp)|Easy|
 |771|[Jewels and Stones](https://leetcode.com/problems/jewels-and-stones/description) | [C++](./algorithms/cpp/jewelsAndStones/JewelsAndStones.cpp)|Easy|
 |643|[Maximum Average Subarray I](https://leetcode.com/problems/maximum-average-subarray-i/description/) | [C++](./algorithms/cpp/maximumAverageSubarray/MaximumAverageSubarray.I.cpp)|Easy|
 |477|[Total Hamming Distance](https://leetcode.com/problems/total-hamming-distance/) | [C++](./algorithms/cpp/totalHammingDistance/totalHammingDistance.cpp)|Medium|

algorithms/cpp/uniqueMorseCodeWords/UniqueMorseCodeWords.cpp

@@ -0,0 +1,67 @@
+// Source : https://leetcode.com/problems/unique-morse-code-words/description/
+// Author : Hao Chen
+// Date   : 2018-06-29
+
+/*************************************************************************************** 
+ *
+ * International orse 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 orse 
+ * 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.
+ ***************************************************************************************/
+
+class Solution {
+public:
+    int uniqueMorseRepresentations(vector<string>& words) {
+        
+        string MorseTable[26] = {".-","-...","-.-.","-..",".","..-.","--.",
+                                 "....","..",".---","-.-",".-..","--","-.",
+                                 "---",".--.","--.-",".-.","...","-","..-",
+                                 "...-",".--","-..-","-.--","--.."};
+        unordered_map<string, bool> transformations;
+        for (auto word : words) {
+            string morse;
+            for (auto ch : word) {
+                morse += MorseTable[ ch - 'a' ];
+            }
+            transformations[morse]=true;
+        }
+        return transformations.size();
+    }
+};