876.md

876. 链表的中间结点

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

Solution

func middleNode(_ head: ListNode?) -> ListNode? {
    var head: ListNode? = head
    var middleHead: ListNode? = head
    
    while head?.next != nil {
        head = head?.next?.next
        middleHead = middleHead?.next
    }
    
    return middleHead
}

Tip

• 快慢指针