131. Palindrome Partitioning

class Solution {public:    vector<vector<string>> ans;    vector<string> ss;    vector<vector<string>> partition(string s) {        if(s.size() == 0)            return ans;        int sz = s.size();        vector<vector<bool>> dp(sz, vector<bool>(sz, false));        for(int i = 0; i < s.size(); ++i) dp[i][i] = true;        for(int i = 0; i < s.size(); ++i)            dfs(dp, s, 0, i);        return ans;    }    void dfs(vector<vector<bool>> &dp, const string &s, int low, int high){        if(low == high || (low==high-1 && s[high] == s[low]) ||(high - low > 1 && s[low] == s[high] && dp[low+1][high-1]) || judge(dp, s, low, high)){            dp[low][high] = true;            ss.push_back(s.substr(low, high-low+1));            if(high == s.size() - 1){                ans.push_back(ss);            }else{                for(int i = high + 1; i < s.size(); ++i){                    dfs(dp, s, high+1, i);                }            }            ss.pop_back();        }    }    bool judge(vector<vector<bool>> &dp, const string &s, int low, int high){        int l, h, sz = high - low + 1, times;        if(sz%2){            l = h = low+sz/2;            times = sz/2 + 1;        }        else{            l = (h = low+sz/2) - 1;            times = sz/2;        }        while(times--){            if(!(l == h || (l==h-1 && s[h] == s[l]) || (high - low > 1 && dp[l+1][h-1] && s[l]==s[h])))                return false;            dp[l][h] = true;            --l;++h;        }        return true;    }};