比较难的一道题，但是还是能看懂

public class Solution {    public List
     
       findRepeatedDnaSequences(String s) {        // ref http://blog.csdn.net/haiyi727/article/details/43752693        int len = s.length();        HashSet
      
        tmp = new HashSet
       
        ();        HashSet
        
          resSet = new HashSet
         
          ();        ArrayList
          
            res = new ArrayList
           
            (); if(len<10) return res; HashMap
            
              map = new HashMap
             
              (); map.put('A',0); map.put('T',1); map.put('C',2); map.put('G',3); int hash = 0; for(int i=0;i