#Linked List

Implement an algorithm to detect a loop in a linked list. Consider edge cases in your approach.

Given a linked list with a cycle, write a method to find and return the node at which the cycle begins. Discuss the logic behind your approach, including any flowchart or diagram if necessary.

Write a function to determine if a linked list has a cycle in it. If there is a cycle, return the node where the cycle begins. Discuss the approach and the time complexity of your solution.

Given a linked list, remove the Nth node from the end of the list. The solution should maintain a linear time complexity and constant space complexity. Provide the implementation details and discuss edge cases.

Explain how to flatten a linked list, which is a list of linked lists, into a single linked list. Discuss your approach, challenges faced, and how you would implement this in your code.