title: How to find String in ArrayList which repeats max number of time?
body: <p>I have an <code>ArrayList&lt;String&gt;</code> with one column which is data time seconds etc.</p>
  
  <p>I want to find max number of repetitions for particular date and time(without seconds). It could be, 
  e.g. 10 values with following parameters 23.12.2012 21:00:. 
  So it must be stated that, say, take only 15 symbols on the left to compare.</p>
  
  <p>The point is that I dont have a value to compare to, because I am not looking for particular value, I am looking for max number of repetitions and of course the value itself* which gave max number of repetitions. <code>ArrayList</code> is sorted in descending order, earliest date first, latest last. <code>ArrayList</code> size is quite big, 170 million raws.</p>
  
  <p>So, how can I approach this task? </p>
  
  <p>Thanks</p>