#0095

Remove Nth Node From End

MediumDSA25 min20 XP

Problem

Given head of a linked list and n, remove the nth node from the end and return the new head.

Why This Matters

This linked-list pattern teaches dummy nodes and pointer gaps, two ideas that remove many edge-case headaches.

Function Signature

def remove_nth_from_end(head, n):

Examples

Example 1

Input1 -> 2 -> 3 -> 4 -> 5, n = 2

Output1 -> 2 -> 3 -> 5

The second node from the end is 4.

Constraints

Return the exact structure requested.
Handle the edge cases mentioned in the prompt.
Prefer clear logic over clever one-liners.

CodePython

class ListNode:
    def __init__(self, val=0, next=None):
        self.val = val
        self.next = next

def remove_nth_from_end(head, n):
    """
    Input example: 1 -> 2 -> 3 -> 4 -> 5, n = 2
    Return: 1 -> 2 -> 3 -> 5
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return head

class ListNode:
    def __init__(self, val=0, next=None):
        self.val = val
        self.next = next

def remove_nth_from_end(head, n):
    """
    Input example: 1 -> 2 -> 3 -> 4 -> 5, n = 2
    Return: 1 -> 2 -> 3 -> 5
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return head

Visible browser tests run here when available.

Testcases1 visible / 3 hidden categories

Core example

Input1 -> 2 -> 3 -> 4 -> 5, n = 2

Expected1 -> 2 -> 3 -> 5

The second node from the end is 4.

Hidden Test Categories

remove headsingle-node listremove tail