title: Data structure with fast indexOf?
body: <p>I need an ordered data structure with O(1) indexOf operation. I store object pointers in the data structure. Any ideas? Some sort of LinkedHashMap?</p>
  
  <p>See what "indexOf" means: <a href="http://download.oracle.com/javase/6/docs/api/java/util/List.html#indexOf%28java.lang.Object%29" rel="noreferrer"><code>List.indexOf(Object)</code></a></p>