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 {
    /**
     * 左右指针, 当两者相等时,跳过右节点,左节点的next指向右节点的next, 右指针前进一步
     当两者不等时,左右指针都前进一步
     *
     * 
     * @param head ListNode类 
     * @return ListNode类
     */
    public ListNode deleteDuplicates (ListNode head) {
        if(head==null){
            return null;
        }
        ListNode pre = head;
        ListNode left = head;
        ListNode right = head.next;
        while(right!=null){
            if(left.val==right.val){
                left.next=right.next;
                right=right.next;
            }else{
                left=left.next;
                right=right.next;
            }
        }
        return pre;
    }
}