title: Regex that validates Active Directory default password complexity
body: <p>I have a list of passwords that I need to examine and determine if they meet the default 3 of 4 rule for AD.  </p>
  
  <p>Rule is contain 3 of the 4 following requirements:
  lower case character (a-z)
  upper case character (A-Z)
  numeric (0-9)
  special character ( !@#$%^&amp;*()_+= )</p>
  
  <p>I am still learning Regex.  I know how to select only those that meet any one character case, but I am not sure how to do 3 of 4.</p>
  
  <p>As a side note, the AD Complexity has two more subtleties that are important (but out of scope of the original question). </p>
  
  <p>It is really 3 of 5.  The fifth is Unicode character.  Be nice to update the Regex with that.</p>
  
  <p>The other is you cannot have the sAMAccountName value in whole in the password (case insensitive), nor if you split the displayName value into tokens split upon space, comma, dash, underscore, pound, pipe and something else those tokens (3 chars and longer) cannot be in whole in the password, case insensitive.</p>