class Main{
  public static void main(String[] args){
    Main m = new Main();
    m.test("7888885466662716666".getBytes());
    m.test("788888546666271888".getBytes());
    m.test("12233344441111222334".getBytes());
  }
 
  private void test(byte[] input){
    String result = findLongestRepeatedSubsequence(input);
    System.out.println("The longest repeating subsequence in " + new String(input) + " is: " + result);
    System.out.println();
    System.out.println("----------");
  }
 
  private String findLongestRepeatedSubsequence(byte[] byteMass){
    // Convert the bytes to a String:
    String bytesAsString = new String(byteMass);
    // Loop as long as this String has at least 1 character:
    while(bytesAsString.length() > 0){
      // Split the String into characters, where each character is a loose String of length 1
      String[] charsAsStringArray = bytesAsString.split("");
      int length = charsAsStringArray.length;
      int maxCount = 0;
      int startingIndex = 0;
      // Loop `i` in the range [0, length_of_String_array)
      for(int i = 0; i < length; i++){
        // Take the substring where the first `i` characters are removed
        String subString = bytesAsString.substring(i);
        String currentChar = charsAsStringArray[i];
        // Count the amount of subsequent times the current character occurs at the start of the substring
        int count = subString.length() - subString.replaceFirst(currentChar+"*", "").length();
        // If this count is larger than our current maxCount:
        if(count > maxCount){
          // Replace the maxCount with this count
          maxCount = count;
          // And set the index where we've found this longest subsequence (`i`) as well
          startingIndex = i;
        }
      }
      // After we've checked all substrings, get the longest subsequence we've found
      String longestSub = bytesAsString.substring(startingIndex, startingIndex + maxCount);
      // Split the entire String with this longest subsequence
      int occurrenceCounter = bytesAsString.split(longestSub, -1).length - 1;
      System.out.println("Current longest subsequence: " + longestSub + ", which occurs " + occurrenceCounter + " time(s)");
      // If we've found a subsequence that occurs at least twice:
      if(occurrenceCounter > 1){
        System.out.println();
        // Return it as result
        return longestSub;
      }
      // If this longest subsequence only occurs once:
      else{
        System.out.println("Before removing: " + bytesAsString);
        // Remove the first character of this found subsequence from the String
        bytesAsString = bytesAsString.substring(0, startingIndex) +
                        (startingIndex < length-1 ? 
                           bytesAsString.substring(startingIndex + 1)
                         :
                           "");
        System.out.println("After removing:  " + bytesAsString);
        System.out.println();
      }
    }
    // Mandatory return if the input is empty
    return null;
  }
}

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