diff --git a/data_structures/linked_list/__init__.py b/data_structures/linked_list/__init__.py index 56b0e51baa93..225113f72cee 100644 --- a/data_structures/linked_list/__init__.py +++ b/data_structures/linked_list/__init__.py @@ -21,8 +21,56 @@ def __init__(self) -> None: self.head: Node | None = None self.size = 0 - def add(self, item: Any) -> None: - self.head = Node(item, self.head) + def add(self, item: Any, position: int = 0) -> None: + """ + Add an item to the LinkedList at the specified position. + Default position is 0 (the head). + + Args: + item (Any): The item to add to the LinkedList. + position (int, optional): The position at which to add the item. + Defaults to 0. + + Raises: + ValueError: If the position is negative or out of bounds. + + >>> linked_list = LinkedList() + >>> linked_list.add(1) + >>> linked_list.add(2) + >>> linked_list.add(3) + >>> linked_list.add(4, 2) + >>> print(linked_list) + 3 --> 2 --> 4 --> 1 + + # Test adding to a negative position + >>> linked_list.add(5, -3) + Traceback (most recent call last): + ... + ValueError: Position must be non-negative + + # Test adding to an out-of-bounds position + >>> linked_list.add(5,7) + Traceback (most recent call last): + ... + ValueError: Out of bounds + >>> linked_list.add(5, 4) + >>> print(linked_list) + 3 --> 2 --> 4 --> 1 --> 5 + """ + if position < 0: + raise ValueError("Position must be non-negative") + + if position == 0 or self.head is None: + new_node = Node(item, self.head) + self.head = new_node + else: + current = self.head + for _ in range(position - 1): + current = current.next + if current is None: + raise ValueError("Out of bounds") + new_node = Node(item, current.next) + current.next = new_node self.size += 1 def remove(self) -> Any: