Two strings, X and Y , are considered similar if either they are identical or we can make them equivalent by swapping at most two letters (in distinct positions) within the string X .
For example, "tars" and "rats" are similar (swapping at positions 0 and 2 ), and "rats" and "arts" are similar, but "star" is not similar to "tars" , "rats" , or "arts" .
Together, these form two connected groups by similarity: {"tars", "rats", "arts"} and {"star"} . Notice that "tars" and "arts" are in the same group even though they are not similar. Formally, each group is such that a word is in the group if and only if it is similar to at least one other word in the group.
We are given a list strs of strings where every string in strs is an anagram of every other string in strs . How many groups are there?
1 <= strs.length <= 3001 <= strs[i].length <= 300strs[i] consists of lowercase letters only.All words in strs have the same length and are anagrams of each other.