title: Determine whether there exists a contiguous subarray of length > 1 with an integer mean
body: <p>Given an unsorted array of integers.</p>
  
  <p>I'm trying to come up with an efficient solution (better than O(n<sup>2</sup>)) but the best I can come up with is an O(n<sup>2</sup>) solution:</p>
  
  <pre><code>for i from 0 to size of list:
      sum = list[i]
  
      for j from i + 1 to size of list:
          sum += list[j]
  
          if sum % (j - i + 1) == 0:
              return true
  return false
  </code></pre>
  
  <p>I've read stuff on sliding window technique, but it looks like that would be useful for subarrays of a specific length <em>k</em>.</p>