title: Alternative representation of a String
body: <p>During the run of my program i create a lot of String(1.000.000) up to size of 700 and my program eats up a lot of memory.These Strings can contain only <code>R,D,L,U</code> as chars so i thought that i could represent them differently.I thought about using BitSet but i am not sure it is more memory efficient.Any ideas?</p>
  
  <p>P.S:i could also shrink the String compressing equal chars<code>(RRRRRRDDDD-&gt;R6D4)</code> but i was hoping for a better solution.</p>