title: how can I compare HashMaps with different keys?
body: <p>I have a clustering algorithm storing the clusters in <code>HashMap&lt;String, ArrayList&lt;String&gt;&gt;</code>.</p>
  
  <p>I need to compare it with the ground truth which is stored in another <code>HashMap&lt;String, ArrayList&lt;String&gt;&gt;</code>.</p>
  
  <p>The keys are not the same, because the array is created by incremental clustering, so I was wondering how can I compare the original clusters with the generated ones.</p>
  
  <p>I'm using NMI and BCUBED as clustering evaluation measures, but my problem is how to refer to the same cluster (ArrayList) if they have different keys..</p>
  
  <p>Any ideas?</p>