# LeetCode - 0893. Groups of Special-Equivalent Strings
### 題目網址：https://leetcode.com/problems/groups-of-special-equivalent-strings/
###### tags: `LeetCode` `Easy` `字串`

/*
    -LeetCode format-
    Problem: 893. Groups of Special-Equivalent Strings
    Difficulty: Easy
    
    by Inversionpeter
*/



class Solution {
    
    string SortStringEvenOdd(string word) {
        string even = "", odd = "", buffer;
        for (int i = 0; i != word.size(); ++i)
            if (i & 1)
                odd += word[i];
            else
                even += word[i];
        sort(odd.begin(), odd.end());
        sort(even.begin(), even.end());
        for (int i = 0; i != word.size(); ++i)
            buffer += (i & 1 ? odd[i >> 1] : even[i >> 1]);
        return buffer;
    }
    
public:
    int numSpecialEquivGroups(vector<string>& A) {
        unordered_set <string> group;
        for (string &s : A)
            group.insert(SortStringEvenOdd(s));
        return group.size();
    }
};