[LeetCode][JavaScript]Remove Duplicates from Sorted List

Remove Duplicates from Sorted List

Given a sorted linked list, delete all duplicates such that each element appear only once.

For example,
Given 1->1->2, return 1->2.
Given 1->1->2->3->3, return 1->2->3.

https://leetcode.com/problems/remove-duplicates-from-sorted-list/

---

从链表中移出重复的节点，链表是有序的，开个变量记下前一个节点就好了。

/**
 * Definition for singly-linked list.
 * function ListNode(val) {
 *     this.val = val;
 *     this.next = null;
 * }
 */
/**
 * @param {ListNode} head
 * @return {ListNode}
 */
var deleteDuplicates = function(head) {
    var h = new ListNode(-1), tail = h, previous = null;
    while(head){
        if(head.val !== previous){
            tail.next = head;
            tail = tail.next;
        }
        previous = head.val;
        head = head.next;
    }
    tail.next = null;
    return h.next;
};