LeetCode 893. 特殊等价字符串组

示例 1：
输入：["a","b","c","a","c","c"]
输出：3
解释：3 组 ["a","a"]，["b"]，["c","c","c"]

示例 2：
输入：["aa","bb","ab","ba"]
输出：4
解释：4 组 ["aa"]，["bb"]，["ab"]，["ba"]

示例 3：
输入：["abc","acb","bac","bca","cab","cba"]
输出：3
解释：3 组 ["abc","cba"]，["acb","bca"]，["bac","cab"]

示例 4：
输入：["abcd","cdab","adcb","cbad"]
输出：1
解释：1 组 ["abcd","cdab","adcb","cbad"]
 
提示：
1 <= A.length <= 1000
1 <= A[i].length <= 20
所有 A[i] 都具有相同的长度。
所有 A[i] 都只由小写字母组成。

class Solution {
public:
    int numSpecialEquivGroups(vector<string>& A) {
        set<string> s;
        string odd, even;
        int i, j;
        for(i = 0; i < A.size(); ++i)
        {
        	even = odd = "";
        	for(j = 0; j < A[i].size(); ++j)
        	{
        		if(j%2)
        			odd.push_back(A[i][j]);
        		else
        			even.push_back(A[i][j]);
        	}
        	sort(odd.begin(), odd.end());
        	sort(even.begin(), even.end());
        	s.insert(odd+even);
        }
        return s.size();
    }
};