leetcode - Palindrome Partitioning

Given a string s, partition s such that every substring of the partition is a palindrome.

Return all possible palindrome partitioning of s.

For example, given s = "aab",
Return

  [    ["aa","b"],    ["a","a","b"]  ]

class Solution {public:    std::vector<std::vector<std::string>> partition(std::string s) {std::vector<std::vector<std::string>> result;std::vector<std::string> ans;dfs(s,ans,result);#if 0for (int i = 0; i < result.size(); i++){for (int j = 0; j < result[i].size(); j++){std::cout << result[i][j] << " ";}std::cout << std::endl;}#endif // 1return result;    }private:void dfs(std::string s,std::vector<std::string> &ans,std::vector<std::vector<std::string>> &result){if(s.size() < 1){result.push_back(ans);return ;}for (int i = 0; i < s.size(); i++){int a = 0,b = i;while(a < b){if(s[a] == s[b]) a++,b--;else break;}if(a >= b){ans.push_back(s.substr(0,i+1));dfs(s.substr(i+1),ans,result);ans.pop_back();}}}};