Leetcode - Remove Sub-Folders from the Filesystem Solution
Poor Man
- Published
- Updated
- Reading time
- 2 min read
- Length
- 261 words
Given a list of folders, remove all sub-folders in those folders and return in any order the folders after removing.
If a folder[i] is located within another folder[j], it is called a sub-folder of it.
The format of a path is one or more concatenated strings of the form: / followed by one or more lowercase English letters. For example, /leetcode and /leetcode/problems are valid paths while an empty string and / are not.
Example 1:
Text
Input: folder = ["/a","/a/b","/c/d","/c/d/e","/c/f"]
Output: ["/a","/c/d","/c/f"]
Explanation: Folders "/a/b/" is a subfolder of "/a" and "/c/d/e" is inside of folder "/c/d" in our filesystem.Example 2:
Text
Input: folder = ["/a","/a/b/c","/a/b/d"]
Output: ["/a"]
Explanation: Folders "/a/b/c" and "/a/b/d/" will be removed because they are subfolders of "/a".Example 3:
Text
Input: folder = ["/a/b/c","/a/b/ca","/a/b/d"]
Output: ["/a/b/c","/a/b/ca","/a/b/d"]Constraints:
1 <= folder.length <= 4 * 10^42 <= folder[i].length <= 100folder[i]contains only lowercase letters and '/'folder[i]always starts with character '/'- Each folder name is unique.
Solution in Python#
Python
class Solution:
@staticmethod
def startswith(string,substring):
return all(x==y for x,y in zip(string,substring))
def removeSubfolders(self, folder: List[str]) -> List[str]:
folder = sorted(i.split("/")[1:] for i in folder)
output = []
prev = [None]
for i in sorted(folder):
if not self.startswith(i,prev):
output.append("/"+"/".join(i))
prev = i
return output