代码随想录链表 02

1. 24. 两两交换链表中的节点

题目链接: LeetCode 24. 两两交换链表中的节点

思路

使用虚拟头节点

我的解法

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/**
 * Definition for singly-linked list.
 * type ListNode struct {
 *     Val int
 *     Next *ListNode
 * }
 */
func swapPairs(head *ListNode) *ListNode {
    dummy := &ListNode{
        Next: head,
    }
    pre := dummy 
    for head != nil && head.Next != nil {
        pre.Next = head.Next
        next := head.Next.Next
        head.Next.Next = head
        head.Next = next
        pre = head 
        head = next
    }
    return dummy.Next
}

2. 19. 删除链表的倒数第 N 个结点

题目链接: LeetCode 19. 删除链表的倒数第 N 个结点

解法

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/**
 * Definition for singly-linked list.
 * type ListNode struct {
 *     Val int
 *     Next *ListNode
 * }
 */
func removeNthFromEnd(head *ListNode, n int) *ListNode {
	dummyNode := &ListNode{0, head}
	fast, slow := dummyNode, dummyNode
	for i := 0; i <= n; i++ { // 注意<=，否则快指针为空时，慢指针正好在倒数第n个上面
		fast = fast.Next
	}
	for fast != nil {
		fast = fast.Next
		slow = slow.Next
	}
	slow.Next = slow.Next.Next
	return dummyNode.Next
}

核心思路

3. 206. 反转链表

题目链接: LeetCode 206. 反转链表

思路

使用双指针

我的解法

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/**
 * Definition for singly-linked list.
 * type ListNode struct {
 *     Val int
 *     Next *ListNode
 * }
 */
func reverseList(head *ListNode) *ListNode {
    var pre *ListNode
    cur := head
    for cur != nil{
        tem := cur.Next
        cur.Next = pre
        pre = cur
        cur = tem
    }
    return pre
}

学习资源

更新日期: 2026-02-20