Delete loop in Linked List

Given a linked list of N nodes such that it may contain a loop.

A loop here means that the last node of the link list is connected to the node at position X. If the link list does not have any loop, X=0.

Remove the loop from the linked list, if it is present.

Examples:

Example 1:

Input: arr[] = N = 3 , value[] = {1,3,4} , X = 2

Output: 1

Explanation: The link list looks like 1 -> 3 -> 4 ^ | |____|
A loop is present. If you remove it successfully, the answer will be 1.

Example 2:

Input: N = 4 ,value[] = {1,8,3,4} , X = 0

Output: 1

Explanation: The Linked list does not contains any loop.

Example 3:

Input: N = 4 , value[] = {1,2,3,4} , X = 1

Output: 1

Explanation:he link list looks like 1 -> 2 -> 3 -> 4 |______________| A loop is present. If you remove it successfully, the answer will be 1.

Constraints:

1 ≤ N ≤ 10^4

Expected time complexity: O(N)

Expected auxiliary space: O(1)