Circular Array Loop

Explore how to use fast and slow pointers to detect cycles in circular arrays. This lesson helps you understand the process of identifying repeating sequences where elements indicate forward or backward steps, honing your skills for coding interviews.

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Statement

There is a circular list of non-zero integers called nums. Each number in the list tells you how many steps to move forward or backward from your current position:

If nums[i] is positive, move nums[i] steps forward.
If nums[i] is negative, move nums[i] steps backward.

As the list is circular:

Moving forward from the last element takes you back to the first element.
Moving backward from the first element takes you to the last element.

A cycle in this list means:

You keep moving according to the numbers, and you end up repeating a sequence of indexes. ...