removenthnodefromendoflist.js

/* 
Given the head of a linked list, remove the nth node from the end of the list and return its head.

Example 1:
Input: head = [1,2,3,4,5], n = 2
Output: [1,2,3,5]

Example 2:
Input: head = [1], n = 1
Output: []

Example 3:
Input: head = [1,2], n = 1
Output: [1]
*/

/**
 * Definition for singly-linked list.
 * function ListNode(val, next) {
 *     this.val = (val===undefined ? 0 : val)
 *     this.next = (next===undefined ? null : next)
 * }
 */
/**
 * @param {ListNode} head
 * @param {number} n
 * @return {ListNode}
 */
var removeNthFromEnd = function (head, n) {
    let arr = [];
    let result = new ListNode();
    let node = result;

    while (head) {
        arr.push(head.val)
        head = head.next;
    }

    arr.splice(arr.length - n, 1);

    arr.forEach(item => {
        node.next = new ListNode(item);
        node = node.next;
    });

    return result.next
};