class Solution {
public:
    vector<vector<string>> partition(string s) {
        int len = s.size();
        vector<vector<bool>> isPalin(len, vector<bool>(len, false));
        for(int i = 0; i < len; ++i)
        {
            for(int j = 0; j <= i; ++j)
            {
                if(s[i] == s[j] && (i - j < 2 || isPalin[j + 1][i - 1]))
                    isPalin[j][i] = true;
            }
        }
        vector<vector<string>> res;
        vector<string> curr;
        backtrack(res, curr, isPalin, s, 0);
        return res;
    }

private:
    void backtrack(vector<vector<string>>& res, vector<string>& curr, const vector<vector<bool>>& isPalin, const string s, int start)
    {
        if(start >= s.size())
        {
            res.push_back(curr);
            return;
        }
        for(int i = start; i < s.size(); ++i)
        {
            if(isPalin[start][i])
            {
                curr.push_back(s.substr(start, i - start + 1));
                backtrack(res, curr, isPalin, s, i + 1);
                curr.pop_back();
            }
        }
    }
};