Linked List | Linked List Cycle in C++ | Data Structure and Algorithm | Hindi

Linked List | Linked List Cycle in C++ | Data Structure and Algorithm | Hindi
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Intuition
When I look at this problem, my first thought is to use two pointers moving through the linked list. The idea is that if there is a cycle in the linked list, at some point, the fast pointer will catch up with the slow pointer.
Approach
I'll use two pointers, one moving at a regular pace (slow pointer) and the other moving twice as fast (fast pointer). If there's a cycle, eventually the fast pointer will catch up with the slow one.
Initialize both pointers to the head of the linked list.
Move the slow pointer one step at a time and the fast pointer two steps at a time.
If there is a cycle, the fast pointer will eventually meet the slow pointer.
If there is no cycle, the fast pointer will reach the end of the list.
Complexity
Time complexity: O(n), where n is the number of nodes in the linked list. In the worst case, the fast pointer would need to traverse the entire list once.
Space complexity: O(1), because I'm only using two pointers regardless of the size of the linked list.