链表反转

[Clear2]

双指针法实现反转

// 通过双指针，遍历head指针
func reverseList(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
}

[Clear2]

测试

func main() {
	node1 := new(ListNode)
	node1.Value = 1
	node2 := new(ListNode)
	node2.Value = 2
	node3 := new(ListNode)
	node3.Value = 3
	node4 := new(ListNode)
	node4.Value = 4
	node5 := new(ListNode)
	node5.Value = 5

	node1.Next = node2
	node2.Next = node3
	node3.Next = node4
	node4.Next = node5
	node5.Next = nil

	//PrintNode(node1)
	resN := reverseList(node1)
	PrintNode(resN)
}

func PrintNode(head * ListNode)  {
	for head != nil {
		fmt.Printf("->%d", head.Value)
		head = head.Next
	}
	fmt.Print("->", head)
}