203.移除链表元素
虚拟头结点法可以解决删除头结点的情况
/**
* 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} val
* @return {ListNode}
*/
var removeElements = function(head, val) {
// 虚拟头结点法
const dummyHead = new ListNode(0, head);
// 这里出错，需要仔细思考
let cur = dummyHead;
while (cur.next) {
if (cur.next.val === val) {
cur.next = cur.next.next;
} else {
cur = cur.next;
}
}
return dummyHead.next;
};
707.设计链表
待更新
206.反转链表
1.双指针法
/**
* Definition for singly-linked list.
* function ListNode(val, next) {
* this.val = (val===undefined ? 0 : val)
* this.next = (next===undefined ? null : next)
* }
*/
/**
* @param {ListNode} head
* @return {ListNode}
*/
var reverseList = function(head) {
// 双指针法
let pre = null;
let cur = head;
let temp = null;
while (cur) {
temp = cur.next;
cur.next = pre;
pre = cur;
cur = temp;
}
// 注意错误
return pre;
};
