[LeetCode 解題報告]131. 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.

Example:

Input: "aab"
Output:
[
  ["aa","b"],
  ["a","a","b"]
]

考察：DFS； 

class Solution {
public:
    vector<vector<string>> partition(string s) {
        vector<vector<string>> res;
        vector<string> out;
        partitionDFS(s, 0, out, res);
        return res;
    }
    
    void partitionDFS(string s, int start, vector<string> &out, vector<vector<string>> &res) {
        if (s.length() == start) {
            res.push_back(out);
            return ;
        }
        
        for (int i = start; i < s.length(); i ++) {
            if (isPalindrome(s, start, i)) {
                out.push_back(s.substr(start, i-start+1));
                partitionDFS(s, i+1, out, res);
                out.pop_back();
            }
        }
    }
    
    bool isPalindrome(string s, int left, int right) {
        while (left < right) {
            if (s[left] != s[right])
                return false;
            left ++, right --;
        }
        return true;
    } 
};