[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"]
  ]

https://oj.leetcode.com/problems/palindrome-partitioning/

思路：因为要返回所有的结果，dfs来做。

public class Solution {
    public List<List<String>> partition(String s) {
        List<List<String>> res = new ArrayList<List<String>>();
        if (s == null || s.length() == 0)
            return res;
        List<String> tmp = new ArrayList<String>();
        part(res, tmp, s);

        return res;
    }

    private void part(List<List<String>> res, List<String> tmp, String s) {
        if ("".equals(s)) {
            res.add(new ArrayList(tmp));
            return;
        }
        for (int i = 1; i <= s.length(); i++) {
            String pre = s.substring(0, i);
            if (isPalin(pre)) {
                tmp.add(pre);
                part(res, tmp, s.substring(i, s.length()));
                tmp.remove(tmp.size()-1);
            }
        }

    }

    private boolean isPalin(String s) {
        if (s == null)
            return false;
        if (s.length() <= 1)
            return true;
        int len = s.length();
        int i = 0, j = len - 1;
        while (i < j) {
            if (s.charAt(i++) != s.charAt(j--))
                return false;
        }
        return true;

    }

    public static void main(String[] args) {
        System.out.println(new Solution().partition("aab"));
    }
}

参考：

http://www.tuicool.com/articles/jmQ3uu

http://blog.csdn.net/worldwindjp/article/details/22066307