Objective

Implement a function that decides whether a singly linked list eventually loops back onto itself or terminates with a NULL pointer.

Steps

• Include list.h in your detect_cycle.c file; it defines the ListNode struct with a void *data payload and a struct ListNode *next pointer.
• Return 1 as soon as you can prove that following next pointers from the head will revisit a node already seen.
• Return 0 when the chain reaches NULL without ever revisiting a node.
• Return 0 when the input pointer is NULL.
• Use constant extra memory, the classic two-pointer (slow / fast) technique is a perfect fit.
• The prototype is int detect_cycle(ListNode *list);.

Objective

Implement a function that decides whether a singly linked list eventually loops back onto itself or terminates with a NULL pointer.

Steps

• Include list.h in your detect_cycle.c file; it defines the ListNode struct with a void *data payload and a struct ListNode *next pointer.
• Return 1 as soon as you can prove that following next pointers from the head will revisit a node already seen.
• Return 0 when the chain reaches NULL without ever revisiting a node.
• Return 0 when the input pointer is NULL.
• Use constant extra memory, the classic two-pointer (slow / fast) technique is a perfect fit.
• The prototype is int detect_cycle(ListNode *list);.