leetcode删除链表的中间节点，快慢指针和链表转数组再转回链表

Posted 2021-12-29 ThinkerWing

5943. 删除链表的中间节点

https://leetcode-cn.com/problems/delete-the-middle-node-of-a-linked-list/

var deleteMiddle = function (head) 
    if (!head.next || !head) return null
    let dummy = new ListNode(-1)
    dummy.next = head
    let slow = dummy, fast = dummy
    while (slow && fast && fast.next) 
        if (!fast.next.next) break; // 为了找到中间节点的前一个，所以提前break
        slow = slow.next
        fast = fast.next.next
    
    slow.next = slow.next.next // 删除节点
    return head
;

var deleteMiddle = function(head) 
 let slow = head
 let res = []
 while(slow)
     res.push(slow.val)
     slow = slow.next
 
   let mid = Math.floor(res.length / 2)
    res.splice(mid,1)
    return arrfn(res)
;
const arrfn = (arr) => 
    let h = new ListNode(0)
    let p = h
    for (let i = 0;i < arr.length;i++) 
        p.next = new ListNode(arr[i])
        p = p.next
    
    return h.next