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 class Solution {
    /**
     *
     * @param head ListNode类
     * @return ListNode类
     */
    public ListNode deleteDuplicates (ListNode head) {
        // write code here
	  //因为是有序链表 所以不考虑哈希表
        if (head == null || head.next == null) return head;
        ListNode fore = head;
	  //单指针模拟
        while (fore.next != null) {
            if (fore.val == fore.next.val) {
			  //若重复 跳过第二个指针
                fore.next = fore.next.next;
            } else {
			  //不重复则继续便利
                fore = fore.next;
            }
        }
        return head;
    }
}