What is Interview Forge?

Interview Forge helps you practice mock interviews, follow study plans, track career goals, review learning analytics, and prepare across 36 pages.

Reverse a Linked List at Apple — Interview Guide

How to approach Reverse a Linked List in a Apple interview: the optimal approach, what Apple interviewers look for, and company-specific tips.

Updated 2026-09EasyLinked Lists

The problem at Apple

Given the head of a singly linked list, reverse it and return the new head.

Apple uses this problem to assess craft, detail, and domain depth. Expect Apple-specific follow-ups that tie the solution back to production reasoning and the company's engineering bar.

Key concepts

Maintain a prev pointer (initially null) and a current pointer.
At each step, save next, point current's next at prev, then advance prev and current.
The recursive version reverses the rest first, then points the next node back at the head.

Approach

def reverse(head):
    prev = None
    while head:
        nxt = head.next
        head.next = prev
        prev = head
        head = nxt
    return prev

Complexity

Variant	Time	Space
Iterative	O(n)	O(1)
Recursive	O(n)	O(n) call stack

Unlock the full guide

Premium members get every DSA, system design, company and role interview guide — plus AI practice, mock interviews, and analytics.

Unlock with Premium