19. Remove Nth Node From End of List(js)
19. Remove Nth Node From End of List
Given a linked list, remove the n-th node from the end of list and return its head.
Example:
Given linked list: 1->2->3->4->5, and n = 2. After removing the second node from the end, the linked list becomes 1->2->3->5.
题意:删除链表的倒数第n个节点
代码如下:
/** * 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) { if(head.next==null) return null; //定义两个指针 let pre=head,cur=head; //让cur沿着head向后移动n个节点 for(let i=0;i<n;i++){ cur=cur.next; } if(!cur) return head.next; //直至cur指向head末端 while(cur.next){ cur=cur.next; pre=pre.next; } pre.next=pre.next.next; return head; };