Fix linear_search docstring return value (#8644)

* updating DIRECTORY.md

* chore: use newest Discord invite link

---------

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

README.md

@@ -13,7 +13,7 @@
     <img src="https://img.shields.io/static/v1.svg?label=Contributions&message=Welcome&color=0059b3&style=flat-square" height="20" alt="Contributions Welcome">
   </a>
   <img src="https://img.shields.io/github/repo-size/TheAlgorithms/Python.svg?label=Repo%20size&style=flat-square" height="20">
-  <a href="https://discord.gg/c7MnfGFGa6">
+  <a href="https://the-algorithms.com/discord">
     <img src="https://img.shields.io/discord/808045925556682782.svg?logo=discord&colorB=7289DA&style=flat-square" height="20" alt="Discord chat">
   </a>
   <a href="https://gitter.im/TheAlgorithms/community">
@@ -42,7 +42,7 @@ Read through our [Contribution Guidelines](CONTRIBUTING.md) before you contribut
 
 ## Community Channels
 
-We are on [Discord](https://discord.gg/c7MnfGFGa6) and [Gitter](https://gitter.im/TheAlgorithms/community)! Community channels are a great way for you to ask questions and get help. Please join us!
+We are on [Discord](https://the-algorithms.com/discord) and [Gitter](https://gitter.im/TheAlgorithms/community)! Community channels are a great way for you to ask questions and get help. Please join us!
 
 ## List of Algorithms
 

data_structures/binary_tree/binary_tree_traversals.py

@@ -58,6 +58,19 @@ def inorder(root: Node | None) -> list[int]:
     return [*inorder(root.left), root.data, *inorder(root.right)] if root else []
 
 
+def reverse_inorder(root: Node | None) -> list[int]:
+    """
+    Reverse in-order traversal visits right subtree, root node, left subtree.
+    >>> reverse_inorder(make_tree())
+    [3, 1, 5, 2, 4]
+    """
+    return (
+        [*reverse_inorder(root.right), root.data, *reverse_inorder(root.left)]
+        if root
+        else []
+    )
+
+
 def height(root: Node | None) -> int:
     """
     Recursive function for calculating the height of the binary tree.
@@ -161,15 +174,12 @@ def zigzag(root: Node | None) -> Sequence[Node | None] | list[Any]:
 
 
 def main() -> None:  # Main function for testing.
-    """
-    Create binary tree.
-    """
+    # Create binary tree.
     root = make_tree()
-    """
-    All Traversals of the binary are as follows:
-    """
 
+    # All Traversals of the binary are as follows:
     print(f"In-order Traversal: {inorder(root)}")
+    print(f"Reverse In-order Traversal: {reverse_inorder(root)}")
     print(f"Pre-order Traversal: {preorder(root)}")
     print(f"Post-order Traversal: {postorder(root)}", "\n")
 

searches/linear_search.py

@@ -15,7 +15,7 @@ def linear_search(sequence: list, target: int) -> int:
     :param sequence: a collection with comparable items (as sorted items not required
         in Linear Search)
     :param target: item value to search
-    :return: index of found item or None if item is not found
+    :return: index of found item or -1 if item is not found
 
     Examples:
     >>> linear_search([0, 5, 7, 10, 15], 0)