Linked structures (ring lists): In a “ring” (circular linked list) data structure, which characteristic correctly defines the linkage among records (nodes)?

Introduction / Context:
Linked lists organize data as nodes connected by pointers. A common variant is the circular linked list (often called a “ring”) where the list loops back to its beginning, enabling continuous traversal and simplifying certain algorithms (e.g., round-robin scheduling). Understanding the structural property that makes a list circular is key to recognizing and implementing this data structure correctly.

Given Data / Assumptions:

• A ring is a linked list with no null terminator at the end.
• Nodes contain data and a pointer (or reference) to the next node.
• We are describing the characteristic linkage that closes the loop.

Concept / Approach:
In a circular (ring) linked list, the last node’s next pointer references the first node. This transforms linear traversal into a cycle. Many algorithms benefit from circularity, including Josephus problem variants and cyclic buffers. Doubly circular lists extend this by linking both next and previous pointers in a loop for efficient bidirectional traversal.

Step-by-Step Solution:

Verification / Alternative check:
Implement a small circular list and print pointers; you will observe that after advancing through all nodes, the next reference from the last node returns to the head.

Why Other Options Are Wrong:

• First points only to last: Not a general property; first usually points to second in singly linked lists.
• Many to one: Describes a graph/fan-in, not a circular list property.
• Each points to all others: Would imply a fully connected graph, not a list.

Common Pitfalls:
Forgetting to update the tail pointer after insertions/deletions; inadvertently creating a cycle in a non-circular list leading to infinite loops.

Final Answer:
Last record points to the first record