131. 分割回文串

class Solution {
public:
    vector<string>path;
    vector<vector<string> >ans;
    void backtracking(string s,int star){
        if(star>=s.size()){
            ans.push_back(path);
            return;
        }
        for(int i=star;i<s.size();i++){
            if(isp(s,star,i)){
                string cnt=s.substr(star,i-star+1);
                path.push_back(cnt);
            }else continue;
            backtracking(s,i+1);
            path.pop_back();
        }
    }
    bool isp(string s,int f,int e){
        for(int i=f, j=e;i<j;i++,j--){
            if(s[i]!=s[j])return false;
        }
        return true;
    }
    vector<vector<string>> partition(string s) {
        backtracking(s,0);
        return ans;
    }
};