<p>You are given an array of strings of the same length <code>words</code>.</p> <p>In one <strong>move</strong>, you can swap any two even indexed characters or any two odd indexed characters of a string <code>words[i]</code>.</p> <p>Two strings <code>words[i]</code> and <code>words[j]</code> are <strong>special-equivalent</strong> if after any number of moves, <code>words[i] == words[j]</code>.</p> <ul> <li>For example, <code>words[i] = "zzxy"</code> and <code>words[j] = "xyzz"</code> are <strong>special-equivalent</strong> because we may make the moves <code>"zzxy" -> "xzzy" -> "xyzz"</code>.</li> </ul> <p>A <strong>group of special-equivalent strings</strong> from <code>words</code> is a non-empty subset of words such that:</p> <ul> <li>Every pair of strings in the group are special equivalent, and</li> <li>The group is the largest size possible (i.e., there is not a string <code>words[i]</code> not in the group such that <code>words[i]</code> is special-equivalent to every string in the group).</li> </ul> <p>Return <em>the number of <strong>groups of special-equivalent strings</strong> from </em><code>words</code>.</p> <p> </p> <p><strong>Example 1:</strong></p> <pre> <strong>Input:</strong> words = ["abcd","cdab","cbad","xyzz","zzxy","zzyx"] <strong>Output:</strong> 3 <strong>Explanation:</strong> One group is ["abcd", "cdab", "cbad"], since they are all pairwise special equivalent, and none of the other strings is all pairwise special equivalent to these. The other two groups are ["xyzz", "zzxy"] and ["zzyx"]. Note that in particular, "zzxy" is not special equivalent to "zzyx". </pre> <p><strong>Example 2:</strong></p> <pre> <strong>Input:</strong> words = ["abc","acb","bac","bca","cab","cba"] <strong>Output:</strong> 3 </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= words.length <= 1000</code></li> <li><code>1 <= words[i].length <= 20</code></li> <li><code>words[i]</code> consist of lowercase English letters.</li> <li>All the strings are of the same length.</li> </ul>