Merge pull request #45 from Reanon/feature/support-go-chapter-stack-q…

…ueue

Feature/support go chapter stack queue

codes/go/chapter_stack_and_queue/array_queue.go

@@ -0,0 +1,92 @@
+// File: array_queue.go
+// Created Time: 2022-11-28
+// Author: Reanon (793584285@qq.com)
+
+package chapter_stack_and_queue
+
+import (
+ "fmt"
+ "strings"
+)
+
+// ArrayQueue 基于环形数组实现的队列, 不支持扩容
+type ArrayQueue struct {
+ data []any // 用于存储队列元素的数组
+ capacity int // 队列容量（即最多容量的元素个数）
+ head int // 头指针，指向队首
+ tail int // 尾指针，指向队尾 + 1
+}
+
+// NewArrayQueue 基于环形数组实现的队列
+func NewArrayQueue(capacity int) *ArrayQueue {
+ return &ArrayQueue{
+ data: make([]any, capacity),
+ capacity: capacity,
+ head: 0,
+ tail: 0,
+ }
+}
+
+// Size 获取队列的长度
+func (q *ArrayQueue) Size() int {
+ size := (q.capacity + q.tail - q.head) % q.capacity
+ return size
+}
+
+// IsEmpty 判断队列是否为空
+func (q *ArrayQueue) IsEmpty() bool {
+ return q.tail-q.head == 0
+}
+
+// Offer 入队
+func (q *ArrayQueue) Offer(v any) {
+ // 当 tail == capacity 表示队列已满
+ if q.Size() == q.capacity {
+ return
+ }
+ // 尾结点后添加
+ q.data[q.tail] = v
+ // 尾指针向后移动一位，越过尾部后返回到数组头部
+ q.tail = (q.tail + 1) % q.capacity
+}
+
+// Poll 出队
+func (q *ArrayQueue) Poll() any {
+ if q.IsEmpty() {
+ return nil
+ }
+ v := q.data[q.head]
+ // 队头指针向后移动，越过尾部后返回到数组头部
+ q.head = (q.head + 1) % q.capacity
+ return v
+}
+
+// Peek 访问队首元素
+func (q *ArrayQueue) Peek() any {
+ if q.IsEmpty() {
+ return nil
+ }
+ v := q.data[q.head]
+ return v
+}
+
+func (q *ArrayQueue) Print() {
+ fmt.Println(q.toString())
+}
+
+// toString 通过字符串的方式输出
+func (q *ArrayQueue) toString() string {
+ // 为空时
+ if q.IsEmpty() {
+ return "empty items"
+ }
+ var builder strings.Builder
+ size := q.Size()
+ str := fmt.Sprintf("%+v", q.data[q.head])
+ for i := 1; i < size; i++ {
+ builder.WriteString(str + " -> ")
+ str = fmt.Sprintf("%+v", q.data[(i+q.head)%q.capacity])
+ }
+ builder.WriteString(str)
+ return builder.String()
+}

codes/go/chapter_stack_and_queue/array_stack.go

@@ -0,0 +1,73 @@
+// File: array_stack.go
+// Created Time: 2022-11-26
+// Author: Reanon (793584285@qq.com)
+
+package chapter_stack_and_queue
+
+import (
+ "fmt"
+ "strconv"
+ "strings"
+)
+
+// ArrayStack 基于数组实现的栈
+type ArrayStack struct {
+ data []int // 数据
+}
+
+func NewArrayStack() *ArrayStack {
+ return &ArrayStack{
+ // 设置栈的长度为 0，容量为 16
+ data: make([]int, 0, 16),
+ }
+}
+
+// Size 栈的长度
+func (s *ArrayStack) Size() int {
+ return len(s.data)
+}
+
+// IsEmpty 栈是否为空
+func (s *ArrayStack) IsEmpty() bool {
+ return s.Size() == 0
+}
+
+// Push 入栈
+func (s *ArrayStack) Push(v int) {
+ // 切片会自动扩容
+ s.data = append(s.data, v)
+}
+
+func (s *ArrayStack) Pop() any {
+ // 弹出栈前，先判断是否为空
+ if s.IsEmpty() {
+ return nil
+ }
+ val := s.Peek()
+ s.data = s.data[:len(s.data)-1]
+ return val
+}
+
+func (s *ArrayStack) Peek() any {
+ if s.IsEmpty() {
+ return nil
+ }
+ val := s.data[len(s.data)-1]
+ return val
+}
+
+func (s *ArrayStack) Print() {
+ fmt.Println(s.toString())
+}
+
+func (s *ArrayStack) toString() string {
+ var builder strings.Builder
+ if s.IsEmpty() {
+ return "empty stack"
+ }
+ for i := len(s.data) - 1; i > 0; i-- {
+ builder.WriteString(strconv.Itoa(s.data[i]) + " -> ")
+ }
+ builder.WriteString(strconv.Itoa(s.data[0]))
+ return builder.String()
+}

codes/go/chapter_stack_and_queue/deque.go

@@ -0,0 +1,26 @@
+// File: deque.go
+// Created Time: 2022-11-29
+// Author: Reanon (793584285@qq.com)
+
+package chapter_stack_and_queue
+
+type Deque interface {
+ // OfferFirst 元素入队
+ OfferFirst(num any)
+ // OfferLast 元素入队
+ OfferLast(num any)
+ // PeekFirst 访问首元素
+ PeekFirst() any
+ // PeekLast 访问尾元素
+ PeekLast() any
+ // PollFirst 元素出队
+ PollFirst() any
+ // PollLast 元素出队
+ PollLast() any
+ // Size 获取队列长度
+ Size() int
+ // IsEmpty 队列是否为空
+ IsEmpty() bool
+ // toString 队列输出为字符串
+ toString() string
+}

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()
+}