public static void main(string[] args) {

        system.out.println(removerepeatedchar("ddddccffgd"));

    }

    public static string removerepeatedchar(string s) {

        if (s == null)

            return s;

        stringbuilder sb = new stringbuilder();

        int i = , len = s.length();

        while (i < len) {

            char c = s.charat(i);

            sb.append(c);

            i++;

            while (i < len && s.charat(i) == c) {

                i++;

            }

        }

        return sb.tostring();

    }

private static string removesamestring(string str)

{

 set<string> mlinkedset = new linkedhashset<string>();

 string[] strarray = str.split(" ");

 stringbuffer sb = new stringbuffer();

 for (int i = ; i < strarray.length; i++)

 {

  if (!mlinkedset.contains(strarray[i]))

  {

   mlinkedset.add(strarray[i]);

   sb.append(strarray[i] + " ");

  }

 }

 system.out.println(mlinkedset);

 return sb.tostring().substring(, sb.tostring().length() - );

  }