1233. Remove Sub-Folders from the Filesystem

https://leetcode.com/problems/remove-sub-folders-from-the-filesystem

Description

Given a list of folders folder, return the folders after removing all sub-folders in those folders. You may return the answer in any order.

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:

**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:

**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:

**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 * 104

• 2 <= folder[i].length <= 100

• folder[i] contains only lowercase letters and '/'.

• folder[i] always starts with the character '/'.

• Each folder name is unique.

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