力扣leetcode 83. 刪除排序鏈表中的重複元素 java

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) { val = x; }
 * }
 */
class Solution {
    public ListNode deleteDuplicates(ListNode head) {
        if(head == null) return null;
        ListNode p = head, q = p.next;
        while(q != null) {
            if(p.val == q.val) p.next = q.next;
            else p = q;
            q = q.next;
        }
        return head;
    }
}