[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Author: pre-commit-ci[bot]

data_structures/persistent_segment_tree.py

@@ -1,11 +1,13 @@
 from typing import List, Optional
 
+
 class Node:
     def __init__(self, value: int = 0) -> None:
         self.value: int = value
         self.left: Optional[Node] = None
         self.right: Optional[Node] = None
 
+
 class PersistentSegmentTree:
     def __init__(self, arr: List[int]) -> None:
         self.n: int = len(arr)
@@ -120,12 +122,15 @@ def _query(self, node: Node, start: int, end: int, left: int, right: int) -> int
         if left <= start and right >= end:
             return node.value
         mid = (start + end) // 2
-        return (self._query(node.left, start, mid, left, right) +
-                self._query(node.right, mid + 1, end, left, right))
+        return self._query(node.left, start, mid, left, right) + self._query(
+            node.right, mid + 1, end, left, right
+        )
+
 
 # Running the doctests
 if __name__ == "__main__":
     import doctest
+
     print("Running doctests...")
     result = doctest.testmod()
     print(f"Ran {result.attempted} tests, {result.failed} failed.")