题解 | #删除有序链表中重复的元素-I#

import java.util.*;

/*
 * public class ListNode {
 *   int val;
 *   ListNode next = null;
 *   public ListNode(int val) {
 *     this.val = val;
 *   }
 * }
 */

public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     *
     * @param head ListNode类
     * @return ListNode类
     */
    public ListNode deleteDuplicates (ListNode head) {
        // write code here
        ListNode slowNode = head;
        if (head == null) return head;
        ListNode fastNode = head.next;
        while (fastNode != null) {
            if (slowNode.val == fastNode.val) {
                slowNode.next = fastNode.next;

            } else {

                slowNode = slowNode.next;
            }
            fastNode = fastNode.next;
        }
        return head;
    }
}

题目条件中给出了链表有序这一条件，只需要将前后相邻两个节点逐个比较即可。