Create removeDuplicateFromString.java

An algorithm which removes duplicates from a given input string

removeDuplicateFromString.java

@@ -0,0 +1,45 @@
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+
+/**
+ *
+ * @author Varun Upadhyay (https://github.com/varunu28)
+ *
+ */
+
+public class removeDuplicateFromString {
+    public static void main (String[] args) throws Exception{
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        String inp_str = br.readLine();
+
+        System.out.println("Actual string is: " + inp_str);
+        System.out.println("String after removing duplicates: " + removeDuplicate(inp_str));
+
+        br.close();
+    }
+
+    /**
+     * This method produces a string after removing all the duplicate characters from input string and returns it
+     * Example: Input String - "aabbbccccddddd"
+     *          Output String - "abcd"
+     * @param s String from which duplicate characters have to be removed
+     * @return string with only unique characters
+     */
+
+    public static String removeDuplicate(String s) {
+        if(s.isEmpty() || s == null) {
+            return s;
+        }
+
+        StringBuilder sb = new StringBuilder("");
+        int n = s.length();
+
+        for (int i = 0; i < n; i++) {
+            if (sb.toString().indexOf(s.charAt(i)) == -1) {
+                sb.append(String.valueOf(s.charAt(i)));
+            }
+        }
+
+        return sb.toString();
+    }
+}