leetcode讲解--893. Groups of Special-Equivalent Strings

题目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: 3Explanation: 3 groups [“a”,“a”], [“b”], [“c”,“c”,“c”]Example 2:Input: [“aa”,“bb”,“ab”,“ba”]Output: 4Explanation: 4 groups [“aa”], [“bb”], [“ab”], [“ba”]Example 3:Input: [“abc”,“acb”,“bac”,“bca”,“cab”,“cba”]Output: 3Explanation: 3 groups [“abc”,“cba”], [“acb”,“bca”], [“bac”,“cab”]Example 4:Input: [“abcd”,“cdab”,“adcb”,“cbad”]Output: 1Explanation: 1 group [“abcd”,“cdab”,“adcb”,“cbad”]Note:1 <= A.length <= 10001 <= A[i].length <= 20All A[i] have the same length.All A[i] consist of only lowercase letters.讲解这道题我刚开始又没看懂，我以为是数组是一个字符串，对这个数组进行奇偶位的swap。后来终于懂了，是对数组中的每个字符串进行奇偶位的swap。Java代码class Solution { public int numSpecialEquivGroups(String[] A) { Set<List> set = new HashSet<>(); for(String s:A){ char[] c = s.toCharArray(); List<Character> temp1 = new ArrayList<>(); if(c.length>2){ List<Character> temp2 = new ArrayList<>(); for(int i=0;i<c.length;i+=2){ temp1.add(c[i]); } Collections.sort(temp1); for(int i=1;i<c.length;i+=2){ temp2.add(c[i]); } Collections.sort(temp2); temp1.addAll(temp2); }else{ for(int i=0;i<c.length;i++){ temp1.add(c[i]); } } set.add(temp1); } return set.size(); }}