Final answer:
The time complexity of searching for a value in a linked list is O(n), as you must traverse through each node sequentially until you find the target value or reach the end of the list.
Step-by-step explanation:
The time complexity of searching a value in a linked list using the most efficient algorithm is in the worst case O(n). Since linked lists do not have index-based access to their elements, you must traverse the list sequentially to find the value. Starting from the head node, you need to visit each node in turn until the desired value is found. In the worst case, where the value is at the last node or not present at all, you will visit every node, leading to a time complexity that is linear relative to the size of the list.