What is the high-level approach for reversing a singly linked list recursively?

• A. Reverse the entire list by swapping data in nodes.
• B. Use a stack to hold all nodes and rebuild in reverse.
• C. Recursively reverse the rest of the list, then set the next node to point back to the current node and set current.next = null.
• D. Iteratively reverse by swapping adjacent nodes.

Answer: (C)

Reversing a singly linked list recursively works by moving to the end of the list and then re-linking as the recursive calls unwind. The idea is to first reverse everything after the current node, so you get a reversed sublist whose head is the last node of the original list. Then you attach the current node behind that reversed part: make the next node point back to the current node, and set the current node’s next to null to mark the new tail. Concretely, you reverse the rest of the list, then do head.next.next = head and head.next = null, returning the new head of the reversed list (the original last node). This pattern uses the call stack to hold state, avoids extra data structures, and runs in linear time.