Remove Nth Node From End
Module 7 · Linked Lists
Problem
Given the head of a linked list, remove the n-th node from the end and return the head. n is guaranteed valid.
Examples
Example 1
Input
head = [1,2,3,4,5], n = 2Output[1,2,3,5]Explanation. removed 4
Example 2
Input
head = [1], n = 1Output[]Explanation. removed the only node — the head
Example 3
Input
head = [1,2], n = 2Output[2]Explanation. removed the head
Constraints
1 ≤ length ≤ 30 · 1 ≤ n ≤ length · follow-up: one pass.
Attempt it first
The module's graduation exercise: it composes the gap runner (surgery pattern 3), the dummy node (pattern 1), and the stand-on-the-predecessor discipline — all in ~10 lines. The examples deliberately include head-removal; let that steer your setup.