How should I practice Reverse a Linked List?

Start by reading the full statement, solve the visible examples, then compare the pattern against related Apple phone screen problems in FastPrep.

Is Reverse a Linked List associated with Apple?

FastPrep tags this as a Apple phone screen coding practice problem when the problem catalog has that company and stage context.

Reverse a Linked List

Apple● EasyNEW GRADPHONE SCREEN

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Problem statement

Given the head of an acyclic singly linked list, reverse all of its next pointers and return the new head. Reuse the original data nodes. An empty list returns null.

Input and output lists are displayed as their node-value sequences. For this exercise, the report's brief reverse-list recollection is practiced as reversal of a singly linked list.

Function

reverseList(head: ListNode) → ListNode

Examples

Example 1

head = [1,2,3,4]return = [4,3,2,1]

The original final node becomes the new head.

Example 2

head = []return = []

Reversing an empty list still produces null.

Constraints

The list contains between 0 and 10000 nodes.
-10^9 <= node.val <= 10^9.