LeetCode——palindrome-partitioning

Question

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"]

]

Solution

求解思想用的是DFS，然后需要记录已经判断过是回文的子字符串，具体实现需要慢慢的体会。

Code

class Solution {
public:
    vector<vector<string>> partition(string s) {
        vector<vector<string>> res;

        vector<string> path;

        dfs(0, s, path, res);

        return res;
    }

    void dfs(int index, string s, vector<string> path, vector<vector<string>>& res) {
        if (index == s.length()) {
            res.push_back(path);
            return;
        }
        for (int i = index; i < s.length(); i++) {
            if (isPalindrome(s, index, i)) {
				path.push_back(s.substr(index, i - index + 1));
            	dfs(i + 1, s, path, res);
            	path.pop_back();
            }
        }
    }
    bool isPalindrome(string s, int start, int end) {
        while (start <= end) {
            if (s[start++] != s[end--])
                return false;
        }
        return true;
    }
    /*
    bool isPalindrome(string s, int start, int end) {
        if (start >= end)
            return true;
        if (s[start] != s[end])
            return false;
        return isPalindrome(s, start++ , end--);
    }
    */
};