Duplicate encoder solution

src/main/java/com/algos/codewars/DuplicateEncoder.java

@@ -0,0 +1,56 @@
+package com.algos.codewars;
+//The goal of this exercise is to convert a string to a new string where each character in the new
+// string is "(" if that character appears only once in the original string, or ")" if that character
+// appears more than once in the original string. Ignore capitalization when determining if a character
+// is a duplicate.
+//        Examples
+//
+//        "din"      =>  "((("
+//        "recede"   =>  "()()()"
+//        "Success"  =>  ")())())"
+//        "(( @"     =>  "))(("
+
+
+import java.util.stream.Collectors;
+
+public class DuplicateEncoder {
+
+    public static void main(String[] args) {
+
+        String text = "din";
+        System.out.println(encode(text));
+
+        text = "recede";
+        System.out.println(encode(text));
+
+        text = "Success";
+        System.out.println(encode(text));
+
+        text = "(( @";
+        System.out.println(encode(text));
+    }
+
+
+//        static String encode(String word){
+//
+//            Set<Character> duplicates  = word.toLowerCase().chars().mapToObj(c -> (char) c)
+//                    .collect(Collectors.groupingBy(c -> c, Collectors.counting()))
+//                    .entrySet()
+//                    .stream().filter(e -> e.getValue() > 1)
+//                    .map(Map.Entry::getKey)
+//                    .collect(Collectors.toSet());
+//
+//            return word.toLowerCase().chars().mapToObj(c -> (char) c).map(c -> {
+//                if (duplicates.contains(c)) {
+//                    return ")";
+//                }
+//                return "(";
+//            }).collect(Collectors.joining());
+//        }
+
+    static String encode(String word) {
+
+        return word.toLowerCase().chars().mapToObj(c -> word.indexOf(c) == word.lastIndexOf(c) ? "(" : ")")
+                .collect(Collectors.joining());
+    }
+}