Correct ruff failures (#8732)

* fix: Correct ruff problems

* updating DIRECTORY.md

* fix: Fix pre-commit errors

* updating DIRECTORY.md

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Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>

searches/binary_tree_traversal.py

@@ -13,11 +13,9 @@ class TreeNode:
         self.left = None
 
 
-def build_tree():
+def build_tree() -> TreeNode:
     print("\n********Press N to stop entering at any point of time********\n")
-    check = input("Enter the value of the root node: ").strip().lower() or "n"
-    if check == "n":
-        return None
+    check = input("Enter the value of the root node: ").strip().lower()
     q: queue.Queue = queue.Queue()
     tree_node = TreeNode(int(check))
     q.put(tree_node)
@@ -37,7 +35,7 @@ def build_tree():
         right_node = TreeNode(int(check))
         node_found.right = right_node
         q.put(right_node)
-    return None
+    raise
 
 
 def pre_order(node: TreeNode) -> None:
@@ -272,7 +270,7 @@ if __name__ == "__main__":
     doctest.testmod()
     print(prompt("Binary Tree Traversals"))
 
-    node = build_tree()
+    node: TreeNode = build_tree()
     print(prompt("Pre Order Traversal"))
     pre_order(node)
     print(prompt() + "\n")