title: Search For keys Matching values in a dictionary of list in C#
body: <p>I have  a dictionary of lists.</p>
  
  <pre><code>var dicAclWithCommonDsEffectivity = new Dictionary&lt;string, List&lt;int&gt;&gt;();
  var list1 = new List&lt;int&gt;(){1,2,3};
  var list2 = new List&lt;int&gt;(){2,4,6};
  var list3 = new List&lt;int&gt;(){3,7,6};
  var list4 = new List&lt;int&gt;(){8,7,6};
  
  dicAclWithCommonDsEffectivity.Add("ab",list1);
  dicAclWithCommonDsEffectivity.Add("bc",list2);
  dicAclWithCommonDsEffectivity.Add("cd",list3);
  dicAclWithCommonDsEffectivity.Add("de",list4);
  </code></pre>
  
  <p>I want to get the keys in dictionary for which atleast one matching value with the current key list.
  for key "ab"(first list). I should get: <code>"ab","bc" and "cd"</code>.Since these lists contain one of the matching element in {1,2,3}</p>
  
  <p>Is there a way without looping through each item in the list of dictionary value.</p>