83. Remove Duplicates from Sorted List

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

For example,
Given1->1->2, return1->2.
Given1->1->2->3->3, return1->2->3.

思路：very 简单，遇到重复的就删掉

public class Solution {
    public ListNode deleteDuplicates(ListNode head) {
        if (head==null||head.next==null){
            return head;
        }

        ListNode prev = head;
        ListNode curr = head;

        while (curr.next!=null){
            prev = curr;
            curr = curr.next;
            if (curr.val==prev.val){
                if (curr.next==null){
                    prev.next = curr.next;
                }else{
                    prev.next = curr.next;
                    curr = prev;
                }
            }
        }

        return head;
    }
}