feat(deque): add implementation of deque

codes/go/chapter_stack_and_queue/deque_test.go

@@ -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()
+ }
+}

codes/go/chapter_stack_and_queue/linkedlist_deque.go

@@ -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()
+}

codes/go/chapter_stack_and_queue/queue_test.go

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