题目83. 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.
public class Solution {
public ListNode deleteDuplicates(ListNode head) {
if(head == null || head.next == null){
return head;
}
int preNum = head.val;
ListNode node = head.next;
ListNode tail = head;
while(node != null){
if(node.val != preNum){
tail.next = node;
tail = tail.next;
}
preNum = node.val;
node = node.next;
}
tail.next = null;
return head;
}
}
