🌗 83. 删除排序链表中的重复元素

难度: 🌗

问题描述

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解法

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode() {}
 *     ListNode(int val) { this.val = val; }
 *     ListNode(int val, ListNode next) { this.val = val; this.next = next; }
 * }
 */
class Solution {
    public ListNode deleteDuplicates(ListNode head) {
        // 思路：
        // 重复元素只保留一个
        if(head == null || head.next == null) {
            return head;
        }
        ListNode pre = head;
        ListNode cur = head.next;
        while(cur != null) {
            if(cur.val == pre.val) {
                ListNode next = cur.next;
                pre.next = next;
                cur = next;
            } else {
                pre = cur;
                cur = cur.next;
            }
        }
        pre.next = null;
        return head;
    }
}

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输出