solves unique morse code mappings

Author: anishLearnsToCode

README.md

@@ -1,7 +1,7 @@
 # LeetCode Algorithms
 
-![problems-solved](https://img.shields.io/badge/Problems%20Solved-187/2081-1f425f.svg)
-![problems-solved-java](https://img.shields.io/badge/Java-187/2081-1abc9c.svg)
+![problems-solved](https://img.shields.io/badge/Problems%20Solved-188/2081-1f425f.svg)
+![problems-solved-java](https://img.shields.io/badge/Java-188/2081-1abc9c.svg)
 ![problems-solved-python](https://img.shields.io/badge/Python-186/2081-1abc9c.svg)
 [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-brightgreen.svg)](CONTRIBUTING.md)
 [![cp](https://img.shields.io/badge/also%20see-Competitve%20Programming-1f72ff.svg)](https://github.com/anishLearnsToCode/competitive-programming)
@@ -216,7 +216,7 @@
 | 788 | [Rotated Digits](https://leetcode.com/problems/rotated-digits) | |
 | 796 | [Rotate String](https://leetcode.com/problems/rotate-string) | [![Java](assets/java.png)](src/RotateString.java)  |
 | 800 | [Similar RGB Color](https://leetcode.com/problems/similar-rgb-color) | |
-| 804 | [Unique Morse Code Words](https://leetcode.com/problems/unique-morse-code-words) | |
+| 804 | [Unique Morse Code Words](https://leetcode.com/problems/unique-morse-code-words) | [![Java](assets/java.png)](src/UniqueMorseCodeWords.java) |
 | 806 | [Number of Lines to Write String](https://leetcode.com/problems/number-of-lines-to-write-string) | |
 | 811 | [Subdomain Visit Count](https://leetcode.com/problems/subdomain-visit-count) | |
 | 812 | [Largest Triangle Area](https://leetcode.com/problems/largest-triangle-area) | |

src/UniqueMorseCodeWords.java

@@ -0,0 +1,32 @@
+import java.util.HashSet;
+import java.util.Set;
+
+public class UniqueMorseCodeWords {
+    private final String[] morseCodeMapping = new String[] {
+            ".-","-...","-.-.","-..",".","..-.",
+            "--.","....","..",".---","-.-",".-..",
+            "--","-.","---",".--.","--.-",".-.",
+            "...","-","..-","...-",".--","-..-",
+            "-.--","--.."
+    };
+
+    public int uniqueMorseRepresentations(String[] words) {
+        Set<String> transformations = new HashSet<>();
+        for (String word : words) {
+            transformations.add(morseValue(word));
+        }
+        return transformations.size();
+    }
+
+    private String morseValue(String word) {
+        StringBuilder result = new StringBuilder();
+        for (char character : word.toCharArray()) {
+            result.append(morseValue(character));
+        }
+        return result.toString();
+    }
+
+    private String morseValue(char character) {
+        return morseCodeMapping[character - 'a'];
+    }
+}