Remove nth or kth node from a singly linked list in single pass

remove-nth-node-linked-list.js

/**
 * Definition for singly-linked list.
 * function ListNode(val) {
 *     this.val = val;
 *     this.next = null;
 * }
 */
/**
 * @param {ListNode} head
 * @param {number} n
 * @return {ListNode}
 */
var removeNthFromEnd = function(head, n) {
    
    let dummyNode = new ListNode(0);
    dummyNode.next = head;
    
    let first = dummyNode;
    let second = dummyNode;
    let counter = 0;
    
    while(counter < n + 1){
        first = first.next;
        counter++;
    }
    
    while(first !== null) {
        first = first.next;
        second = second.next;
    }
    
    second.next = second.next.next;
    return dummyNode.next;
};