Given a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list.
For example,Given1->2->3->3->4->4->5, return1->2->5.
Given1->1->1->2->3, return 2->3.
public class Solution {
public ListNode deleteDuplicates(ListNode head) {
ListNode dummy = new ListNode(-1);
dummy.next = head;
ListNode tail = dummy;
ListNode p1 = head;
ListNode p2 = head;
while(p1!=null&&p1.next!=null)
{
while(p1.next != null&&p1.val == p1.next.val)
{
p1 = p1.next;
}
if(p1 == p2)
{
tail.next = p2;
tail = tail.next;
}
p2 = p1.next;
p1 = p2;
}
tail.next = p1; // 加入最后一个元素
return dummy.next;
}
}
