Skip to content

1233. Remove Sub-Folders from the Filesystem 👍

  • Time: $O(\texttt{sort})$
  • Space: $O(n)$
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
class Solution {
 public:
  vector<string> removeSubfolders(vector<string>& folder) {
    vector<string> ans;
    string prev;

    ranges::sort(folder);

    for (const string& f : folder) {
      if (!prev.empty() && f.find(prev) == 0 && f[prev.length()] == '/')
        continue;
      ans.push_back(f);
      prev = f;
    }

    return ans;
  }
};

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
class Solution {
  public List<String> removeSubfolders(String[] folder) {
    List<String> ans = new ArrayList<>();
    String prev = "";

    Arrays.sort(folder);

    for (final String f : folder) {
      if (!prev.isEmpty() && f.startsWith(prev) && f.charAt(prev.length()) == '/')
        continue;
      ans.add(f);
      prev = f;
    }

    return ans;
  }
}

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
class Solution:
  def removeSubfolders(self, folder: list[str]) -> list[str]:
    ans = []
    prev = ""

    folder.sort()

    for f in folder:
      if len(prev) > 0 and f.startswith(prev) and f[len(prev)] == '/':
        continue
      ans.append(f)
      prev = f

    return ans