Delete SubStrings

http://instant.1point3acres.com/thread/134194
Delete SubStrings: 给一个String s和一个String t, 返回一共能在s中删除t多少次。 例如s = aabb, t = ab, return = 2; s = aabcbdc, t = abc, return 1; 

  static int deleteSubStrings(String a, String b, Map<String, Integer> dp) {
    if (dp.containsKey(a))
      return dp.get(a);
    int ret = 0;
    for (int i = 0; i < a.length(); i++) {
      if (a.startsWith(b, i)) {
        ret = Math.max(ret,
            1 + deleteSubStrings(a.substring(0, i) + a.substring(i + b.length()), b, dp));
      }
    }
    dp.put(a, ret);
    return ret;
  }
  public static void main(String[] args) {
    System.out.println(deleteSubStrings("aabb", "ab", new HashMap<String, Integer>()));
    System.out.println(deleteSubStrings("aabcbdc", "abc", new HashMap<String, Integer>()));
  }

http://www.mitbbs.com/article_t/Recommend/31524609.html