go 反转一个单链表

输入: 1->2->3->4->5->NULL
输出: 5->4->3->2->1->NULL

代码实现

// ListNode Definition for singly-linked list.
type ListNode struct {
    Val  int
    Next *ListNode
}

func reverseList(head *ListNode) *ListNode {
    if head == nil || head.Next == nil {
        return head
    }

    var prev *ListNode
    cur := head
    for cur != nil {
        cur.Next, prev, cur = prev, cur, cur.Next
    }
    return prev
}