Given a linked list, detect if there is a loop in it. If a loop exists, find the starting point of the loop.

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Accepted Answer

Detecting a loop in a linked list is crucial for preventing infinite traversal and ensuring efficient memory usage.

Floyd's Cycle Detection Algorithm: This algorithm uses two pointers, slow and fast, to traverse the list. If they meet, a loop exists.
Time Complexity: The algorithm runs in O(n) time, where n is the number of nodes in the linked list, making it efficient.
Space Complexity: It uses O(1) space since it only requires two pointers, regardless of the list size.
Example: In a linked list with nodes 1 -> 2 -> 3 -> 4 -> 2 (loop back to node 2), the slow and fast pointers will eventually meet.
Implementation: The algorithm can be implemented in various programming languages, such as Python, Java, or C++.

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