# GeetCode Hub

You are given an array `words` of strings.

A move onto `s` consists of swapping any two even indexed characters of `s`, or any two odd indexed characters of `s`.

Two strings `s` and `t` are special-equivalent if after any number of moves onto `s`, `s == t`.

For example, `s = "zzxy"` and `t = "xyzz"` are special-equivalent because we may make the moves `"zzxy" -> "xzzy" -> "xyzz"` that swap `s[0]` and `s[2]`, then `s[1]` and `s[3]`.

Now, a group of special-equivalent strings from `words` is a non-empty subset of `words` such that:

1. Every pair of strings in the group are special equivalent, and;
2. The group is the largest size possible (ie., there isn't a string `s` not in the group such that `s` is special equivalent to every string in the group)

Return the number of groups of special-equivalent strings from `words`.

Example 1:

```Input: words = ["abcd","cdab","cbad","xyzz","zzxy","zzyx"]
Output: 3
Explanation:
One group is ["abcd", "cdab", "cbad"], since they are all pairwise special equivalent, and none of the other strings are 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".
```

Example 2:

```Input: words = ["abc","acb","bac","bca","cab","cba"]
Output: 3```

Note:

• `1 <= words.length <= 1000`
• `1 <= words[i].length <= 20`
• All `words[i]` have the same length.
• All `words[i]` consist of only lowercase letters.

class Solution { public int numSpecialEquivGroups(String[] words) { } }