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.
难点就一个，就是要考虑到连续3个和3个以上的情况。
/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode(int x) { val = x; }
* }
*/
public class Solution {
public ListNode deleteDuplicates(ListNode head) {
if(head != null)
{
ListNode nodeA = head;
ListNode nodeB = head.next;
while(nodeB != null)
{
if(nodeA.val == nodeB.val){
nodeA.next = nodeB.next;
nodeB = nodeB.next;
}else{
nodeA = nodeB;
nodeB = nodeB.next;
}
}
}
return head;
}
}