numSpecialEquivGroups.go

/* https://leetcode.com/problems/groups-of-special-equivalent-strings/description/
You are given an array A of strings.

Two strings S and T are special-equivalent if after any number of moves, S == T.

A move consists of choosing two indices i and j with i % 2 == j % 2, and swapping S[i] with S[j].

Now, a group of special-equivalent strings from A is a non-empty subset S of A such that any string not in S is not special-equivalent with any string in S.

Return the number of groups of special-equivalent strings from A.


Example 1:

	Input: ["a","b","c","a","c","c"]
	Output: 3
	Explanation: 3 groups ["a","a"], ["b"], ["c","c","c"]

Example 2:

	Input: ["aa","bb","ab","ba"]
	Output: 4
	Explanation: 4 groups ["aa"], ["bb"], ["ab"], ["ba"]

Example 3:

	Input: ["abc","acb","bac","bca","cab","cba"]
	Output: 3
	Explanation: 3 groups ["abc","cba"], ["acb","bca"], ["bac","cab"]

Example 4:

	Input: ["abcd","cdab","adcb","cbad"]
	Output: 1
	Explanation: 1 group ["abcd","cdab","adcb","cbad"]

Note:

	1 <= A.length <= 1000
	1 <= A[i].length <= 20
	All A[i] have the same length.
	All A[i] consist of only lowercase letters.
*/

package lstring

func numSpecialEquivGroups(A []string) int {
	maps := map[[52]int8]bool{}
	for _, word := range A {
		key := [52]int8{}
		for i := 0; i < len(word); i += 2 {
			key[int(word[i])-'a']++
			if i+1 < len(word) {
				key[26+int(word[i+1])-'a']++
			}
		}
		maps[key] = true
	}
	return len(maps)
}