class Solution {

public:

    vector<vector<string>> partition(string s) {

        vector<vector<string>> res={{}};

        for(int i=;i<s.length();i++){

            string si="";

            si.push_back(s[i]);

            res[].push_back(si);

            merge(s,si,res,i-,i+);

        }

        return res;

    }

    void merge(string s,string cur,vector<vector<string>>& res,int start,int end){

        if(start< || end>=s.length()) return;

        if(s[start]!=s[end]) return;

        cur=s[start]+cur+s[end];

        res[].push_back(cur);

        merge(s,cur,res,start-,end+);

    }

};