Palindrome Partitioning

注意add arraylist<E> 到 ArrayList<ArrayList<E>>的时候传递引用和传值得区别！！！
 1 public class Solution {
 2     public ArrayList<ArrayList<String>> partition(String s) {
 3         // IMPORTANT: Please reset any member data you declared, as
 4         // the same Solution instance will be reused for each test case.
 5         ArrayList<ArrayList<String>> result = new ArrayList<ArrayList<String>>();
 6         if(s == null || s.length() == 0)
 7             return result;
 8         ArrayList<String> stringList = new ArrayList<String>();
 9         PaPartition(s, 0, s.length(), stringList, result);
10         return result;
11     }
12     private boolean isPalindrome(String s, int start, int end)
13     {
14         while(start < end - 1)
15         {
16             if(s.charAt(start) != s.charAt(end - 1))
17                 return false;
18             start ++;
19             end --;
20         }
21         return true;
22     }
23     private void PaPartition(String s, int start, int end, ArrayList<String> stringList, ArrayList<ArrayList<String>> result)
24     {
25         if(start >= end)
26         {
27             ArrayList<String> tmp = new ArrayList<String>();
28 　　　　　　　tmp.addAll(stringList);
29             result.add(tmp);
30             return;
31         }
32         for(int i = start + 1; i <= end; i++)
33         {
34             if(isPalindrome(s, start, i))
35             {
36                 stringList.add(s.substring(start, i));
37                 PaPartition(s, i, end, stringList, result);
38                 stringList.remove(stringList.size() - 1);
39             }
40         }
41     }
42 }