feat(deque): add implementation of deque

This commit is contained in:
reanon 2022-11-29 10:43:47 +08:00
parent 19469aecbf
commit a554590fa8
3 changed files with 155 additions and 1 deletions

View file

@ -0,0 +1,53 @@
// File: deque_test.go
// Created Time: 2022-11-29
// Author: Reanon (793584285@qq.com)
package chapter_stack_and_queue
import "testing"
func TestLinkedListDeque(t *testing.T) {
// 初始化队列
var deque Deque
deque = NewLinkedListDeque()
// 元素入队
deque.OfferLast(2)
deque.OfferLast(5)
deque.OfferLast(4)
deque.OfferFirst(3)
deque.OfferFirst(1)
t.Log("队列 deque = ", deque.toString())
// 访问队首元素
peekFirst := deque.PeekFirst()
t.Log("队首元素 peek = ", peekFirst)
peekLast := deque.PeekLast()
t.Log("队尾元素 peek = ", peekLast)
// 元素出队
pollFirst := deque.PollFirst()
t.Log("队首出队元素 pollFirst = ", pollFirst, ",队首出队后 deque = ", deque.toString())
pollLast := deque.PollLast()
t.Log("队尾出队元素 pollLast = ", pollLast, ",队尾出队后 deque = ", deque.toString())
// 获取队的长度
size := deque.Size()
t.Log("队的长度 size = ", size)
// 判断是否为空
isEmpty := deque.IsEmpty()
t.Log("队是否为空 = ", isEmpty)
}
// BenchmarkArrayQueue 67.92 ns/op in Mac M1 Pro
func BenchmarkLinkedListDeque(b *testing.B) {
stack := NewLinkedListDeque()
// use b.N for looping
for i := 0; i < b.N; i++ {
stack.OfferLast(777)
}
for i := 0; i < b.N; i++ {
stack.PollFirst()
}
}

View file

@ -0,0 +1,102 @@
// File: linkedlist_deque.go
// Created Time: 2022-11-29
// Author: Reanon (793584285@qq.com)
package chapter_stack_and_queue
import (
"container/list"
"fmt"
"strings"
)
// LinkedListDeque 基于链表实现的双端队列, 使用内置包 list 来实现栈
type LinkedListDeque struct {
list *list.List
}
// NewLinkedListDeque 初始化双端队列
func NewLinkedListDeque() *LinkedListDeque {
return &LinkedListDeque{
list: list.New(),
}
}
// OfferFirst 元素入队
func (s *LinkedListDeque) OfferFirst(value any) {
s.list.PushFront(value)
}
// OfferLast 元素入队
func (s *LinkedListDeque) OfferLast(value any) {
s.list.PushBack(value)
}
// PollFirst 元素出队
func (s *LinkedListDeque) PollFirst() any {
if s.IsEmpty() {
return nil
}
e := s.list.Front()
s.list.Remove(e)
return e.Value
}
// PollLast 元素出队
func (s *LinkedListDeque) PollLast() any {
if s.IsEmpty() {
return nil
}
e := s.list.Back()
s.list.Remove(e)
return e.Value
}
// PeekFirst 访问首元素
func (s *LinkedListDeque) PeekFirst() any {
if s.IsEmpty() {
return nil
}
e := s.list.Front()
return e.Value
}
// PeekLast 访问尾元素
func (s *LinkedListDeque) PeekLast() any {
if s.IsEmpty() {
return nil
}
e := s.list.Back()
return e.Value
}
// Size 获取队列的长度
func (s *LinkedListDeque) Size() int {
return s.list.Len()
}
// IsEmpty 判断队列是否为空
func (s *LinkedListDeque) IsEmpty() bool {
return s.list.Len() == 0
}
func (s *LinkedListDeque) Print() {
fmt.Println(s.toString())
}
func (s *LinkedListDeque) toString() string {
var builder strings.Builder
if s.IsEmpty() {
fmt.Println("empty stack")
}
e := s.list.Front()
// 强转为 string, 会影响效率
str := fmt.Sprintf("%v", e.Value)
for e.Next() != nil {
builder.WriteString(str + " -> ")
e = e.Next()
str = fmt.Sprintf("%v", e.Value)
}
builder.WriteString(str)
return builder.String()
}

View file

@ -7,7 +7,6 @@ package chapter_stack_and_queue
import "testing" import "testing"
func TestArrayQueue(t *testing.T) { func TestArrayQueue(t *testing.T) {
// 初始化队列,使用队列的通用接口 // 初始化队列,使用队列的通用接口
var queue Queue var queue Queue
capacity := 10 capacity := 10