一起养成写作习惯！这是我参与「掘金日新计划 · 4 月更文挑战」的第10天，点击查看活动详情。
Given the head of a sorted linked list,
delete all duplicates such that each element appears only once
. Return
the linked list sorted as well
.
Example 1:
Input: head = [1,1,2]
Output: [1,2]
Example 2:
Input: head = [1,1,2,3,3]
Output: [1,2,3]
Constraints:
-
The number of nodes in the list is in the range
[0, 300]. -
-100 <= Node.val <= 100 -
The list is guaranteed to be sorted in ascending order.
package com.linkedlist;
/**
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@Author you guess
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@Date 2022/4/1 17:17
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@Version 1.0
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@Desc 删除重复节点（如果有2个节点值相同，只保留1个节点；重复的节点只保留一个） */ public class Leetcode_83_RemoveDuplicatesfromSortedList {
public static void main(String[] args) { ListNode node72 = new ListNode(7, null); ListNode node7 = new ListNode(7, node72); ListNode node6 = new ListNode(6, node7); ListNode node5 = new ListNode(5, node6); ListNode node42 = new ListNode(4, node5); ListNode node41 = new ListNode(4, node42); ListNode node40 = new ListNode(4, node41); ListNode node3 = new ListNode(3, node40); ListNode node22 = new ListNode(2, node3); ListNode node21 = new ListNode(2, node22); ListNode node20 = new ListNode(2, node21); ListNode node11 = new ListNode(1, node20); ListNode node1 = new ListNode(1, node11); Leetcode_83_RemoveDuplicatesfromSortedList main = new Leetcode_83_RemoveDuplicatesfromSortedList(); main.printListNode(main.deleteDuplicates(node1)); }
/**
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Runtime: 0 ms, faster than 100.00% of Java online submissions for Remove Duplicates from Sorted List.
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Memory Usage: 41.6 MB, less than 94.40% of Java online submissions for Remove Duplicates from Sorted List.
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每次:head与head.next值相等时，pre.next = head.next
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head与head.next值不相等时，pre=最后一个重复值，head=下一个值
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@param head
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@return */ public ListNode deleteDuplicates(ListNode head) { ListNode sentinel = new ListNode(0, head); ListNode pre = sentinel; while (head != null) { if (head.next != null && head.val == head.next.val) { pre.next = head.next; head = head.next; } else { pre = pre.next; //pre指向的链表也是连续的 head = head.next; } } return sentinel.next; }
public void printListNode(ListNode head) { while (head != null) { System.out.println(head.val); head = head.next; } }
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}
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end
