leetcode893

class Solution {
public:
    int numSpecialEquivGroups(vector<string>& A) {
        set<string> ST;

        for (auto a : A)
        {
            vector<char> V1;
            vector<char> V2;
            for (int i = 0; i < a.length(); i++)
            {
                if (i % 2 == 0)//下标偶数位:0 2 4 6 8...
                {
                    V1.push_back(a[i]);
                }
                else//下标奇数位1 3 5 7 9...
                {
                    V2.push_back(a[i]);
                }
            }
            sort(V1.begin(), V1.end());
            sort(V2.begin(), V2.end());
            string X = "";
            for (auto v : V1)
            {
                X.push_back(v);
            }
            for (auto v : V2)
            {
                X.push_back(v);
            }
            if (ST.find(X) == ST.end())//没有这条记录
            {
                ST.insert(X);
            }
        }
        int count = ST.size();
        return count;
    }
};