在之前实现的基础上调整单链表和队列的接口。
将size变量移到list中。
type Queue struct {
list *SinglyLinkedList
}
func NewQueue() *Queue {
return &Queue{
list: &SinglyLinkedList{},
}
}
func (o *Queue) Len() int {
return o.list.Len()
}
func (o *Queue) IsEmpty() bool {
return o.list.Len() == 0
}
func (o *Queue) Push(v interface{}) {
o.list.AddToTail(v)
}
func (o *Queue) Peek() interface{} {
if o.IsEmpty() {
panic("Queue is empty")
}
return o.list.Head().V
}
func (o *Queue) Pop() interface{} {
if o.IsEmpty() {
panic("Queue is empty")
}
node := o.list.Head()
o.list.RemoveHead()
return node.V
}
// 单链表节点
type SLLNode struct {
V interface{}
Next *SLLNode
}
// 单链表
type SinglyLinkedList struct {
head *SLLNode
tail *SLLNode // 尾节点。使得在尾部添加节点的时间复杂度是O(1)
size int
}
func (o *SinglyLinkedList) Len() int {
return o.size
}
func (o *SinglyLinkedList) AddToHead(v interface{}) {
o.head = &SLLNode{
V: v,
Next: o.head,
}
if o.tail == nil {
o.tail = o.head
}
o.size++
}
func (o *SinglyLinkedList) Head() *SLLNode {
return o.head
}
func (o *SinglyLinkedList) RemoveHead() {
if o.head == nil {
panic("SinglyLinkedList. head is nil")
}
o.head = o.head.Next
if o.head == nil {
o.tail = nil
}
o.size--
}
func (o *SinglyLinkedList) AddToTail(v interface{}) {
node := &SLLNode{
V: v,
}
if o.tail != nil {
o.tail.Next = node
o.tail = node
} else {
o.head = node
o.tail = node
}
o.size++
}
