1
class Solution {
2
  public List<String> findRepeatedDnaSequences(String s) {
3
    HashMap<String, Integer> map = new HashMap();
4
    int i = 0;
5
    int j = 0;
6
    int k = 10;
7
    StringBuilder sb = new StringBuilder("");
8

9
    while (j < s.length()) {
10
      sb.append(s.charAt(j));
11
      if (j - i + 1 < k) {
12
        j++;
13
      } else if (j - i + 1 == k) {
14
        if (!map.containsKey(sb.toString())) {
15
          map.put(sb.toString(), 1);
16
        } else {
17
          map.put(sb.toString(), map.get(sb.toString()) + 1);
18
        }
19
        sb.deleteCharAt(0);
20
        i++;
21
        j++;
22
      }
23
    }
24
    List<String> list = new ArrayList();
25
    for (Map.Entry<String, Integer> mapElement : map.entrySet()) {
26
      if (mapElement.getValue() > 1) {
27
        list.add(mapElement.getKey());
28
      }
29
    }
30
    return list;
31
  }
32
}