运用快慢指针
class Solution { public ListNode middleNode(ListNode head) { ListNode fast=head; ListNode slow=head; while(fast!=null&&fast.next!=null){ fast=fast.next.next; slow=slow.next; } return slow; } }
fast!=null是偶数个结点的判断条件,fast.next!=null,是奇数结点的判断条件
运用快慢指针
class Solution { public ListNode middleNode(ListNode head) { ListNode fast=head; ListNode slow=head; while(fast!=null&&fast.next!=null){ fast=fast.next.next; slow=slow.next; } return slow; } }
fast!=null是偶数个结点的判断条件,fast.next!=null,是奇数结点的判断条件