package main
import "fmt"
//链表节点
type ListNode struct {
Val int
Next *ListNode
}
//反转链表的实现
func reverseListV1(head *ListNode) *ListNode {
if head == nil {
return nil
}
var newHead *ListNode
for head != nil {
node := head.Next
head.Next = newHead
newHead = head
head = node
}
return newHead
}
func reverseListV2(head *ListNode) *ListNode {
if head == nil {
return nil
}
var newHead *ListNode
for head != nil {
head.Next, newHead, head = newHead, head, head.Next
}
return newHead
}
func main() {
head := new(ListNode)
head.Val = 1
ln2 := new(ListNode)
ln2.Val = 2
ln3 := new(ListNode)
ln3.Val = 3
ln4 := new(ListNode)
ln4.Val = 4
ln5 := new(ListNode)
ln5.Val = 5
head.Next = ln2
ln2.Next = ln3
ln3.Next = ln4
ln4.Next = ln5
//pre := reverseListV1(head)
//fmt.Println(pre)
pre2 := reverseListV2(head)
fmt.Println(pre2)
}
