Remove nth Node from end of list

Link

https://leetcode.com/problems/remove-nth-node-from-end-of-list/

Deadline

Mar 12, 2022

Status

Archived

Type

linked list

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]

Constraints:

The number of nodes in the list is sz.

1 <= sz <= 30

0 <= Node.val <= 100

1 <= n <= sz

풀이

은찬


const removeNthFromEnd = (head, n) => {
    let current = head;
    let prev = head;
    
    for(let i = 0; i < n; i++){
        current = current.next;
    }
    
    if(!current){
        return head.next;
    }
    
    while(current.next){
        current = current.next;
        prev = prev.next;
    }
    
    prev.next = prev.next.next;
    
    return head;
};

재영


/**
 * 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 nodeHead = head;
    
    const lists = {};    
    lists.length = 0;
    
    let index = 0;

    while (true) {
        lists[index] = nodeHead;
        nodeHead = nodeHead.next;
        index += 1;
        lists.length += 1;
        
        if (nodeHead === null) {
            break;
        }
    }
    
    const targetIndex = lists.length - n;
    
    if (targetIndex === 0) {
        head = head.next;
        return head;
    }
    
    lists[targetIndex - 1].next = lists[targetIndex].next; // 연결리스트를 이어줌.
    
    return head
};

// 56ms, 98% fast