Create remove-sub-folders-from-the-filesystem.py

Author: kamyu104

Python/remove-sub-folders-from-the-filesystem.py

@@ -0,0 +1,35 @@
+# Time:  O(n), n is the total sum of the lengths of folder names
+# Space: O(t), t is the number of nodes in trie
+
+import collections
+import itertools
+
+
+class Solution(object):
+    def removeSubfolders(self, folder):
+        """
+        :type folder: List[str]
+        :rtype: List[str]
+        """
+        def dfs(curr, path, result):
+            if "_end" in curr:
+                result.append("/" + "/".join(path))
+                return
+            for c in curr:
+                if c == "_end":
+                    continue
+                path.append(c)
+                dfs(curr[c], path, result)
+                path.pop()
+
+        _trie = lambda: collections.defaultdict(_trie)
+        trie = _trie()
+        for f in folder:
+            f_list = f.split("/")
+            reduce(dict.__getitem__,
+                   itertools.islice(f_list, 1, len(f_list)),
+                   trie).setdefault("_end")
+        result = []
+        dfs(trie, [], result)
+        return result
+