diff --git a/codes/go/chapter_stack_and_queue/array_queue.go b/codes/go/chapter_stack_and_queue/array_queue.go
new file mode 100644
index 0000000..f771ea2
--- /dev/null
+++ b/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()
+}
diff --git a/codes/go/chapter_stack_and_queue/array_stack.go b/codes/go/chapter_stack_and_queue/array_stack.go
new file mode 100644
index 0000000..f3a8a28
--- /dev/null
+++ b/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()
+}
diff --git a/codes/go/chapter_stack_and_queue/deque.go b/codes/go/chapter_stack_and_queue/deque.go
new file mode 100644
index 0000000..3ac070e
--- /dev/null
+++ b/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
+}
diff --git a/codes/go/chapter_stack_and_queue/deque_test.go b/codes/go/chapter_stack_and_queue/deque_test.go
new file mode 100644
index 0000000..c0eaf08
--- /dev/null
+++ b/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()
+	}
+}
diff --git a/codes/go/chapter_stack_and_queue/linkedlist_deque.go b/codes/go/chapter_stack_and_queue/linkedlist_deque.go
new file mode 100644
index 0000000..62a6149
--- /dev/null
+++ b/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()
+}
diff --git a/codes/go/chapter_stack_and_queue/linkedlist_queue.go b/codes/go/chapter_stack_and_queue/linkedlist_queue.go
new file mode 100644
index 0000000..5b62ac3
--- /dev/null
+++ b/codes/go/chapter_stack_and_queue/linkedlist_queue.go
@@ -0,0 +1,78 @@
+// File: linkedlist_queue.go
+// Created Time: 2022-11-28
+// Author: Reanon (793584285@qq.com)
+
+package chapter_stack_and_queue
+
+import (
+	"container/list"
+	"fmt"
+	"strings"
+)
+
+// LinkedListQueue 基于链表实现的队列, 使用内置包 list 来实现栈
+type LinkedListQueue struct {
+	list *list.List
+}
+
+// NewLinkedListQueue 初始化链表
+func NewLinkedListQueue() *LinkedListQueue {
+	return &LinkedListQueue{
+		list: list.New(),
+	}
+}
+
+// Offer 入队
+func (s *LinkedListQueue) Offer(value any) {
+	s.list.PushBack(value)
+}
+
+// Poll 出队
+func (s *LinkedListQueue) Poll() any {
+	if s.IsEmpty() {
+		return nil
+	}
+	e := s.list.Front()
+	s.list.Remove(e)
+	return e.Value
+}
+
+// Peek 访问队首元素
+func (s *LinkedListQueue) Peek() any {
+	if s.IsEmpty() {
+		return nil
+	}
+	e := s.list.Front()
+	return e.Value
+}
+
+// Size 获取队列的长度
+func (s *LinkedListQueue) Size() int {
+	return s.list.Len()
+}
+
+// IsEmpty 判断队列是否为空
+func (s *LinkedListQueue) IsEmpty() bool {
+	return s.list.Len() == 0
+}
+
+func (s *LinkedListQueue) Print() {
+	fmt.Println(s.toString())
+}
+
+func (s *LinkedListQueue) 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()
+}
diff --git a/codes/go/chapter_stack_and_queue/linkedlist_stack.go b/codes/go/chapter_stack_and_queue/linkedlist_stack.go
new file mode 100644
index 0000000..24f46ac
--- /dev/null
+++ b/codes/go/chapter_stack_and_queue/linkedlist_stack.go
@@ -0,0 +1,78 @@
+// File: linkedlist_stack.go
+// Created Time: 2022-11-28
+// Author: Reanon (793584285@qq.com)
+
+package chapter_stack_and_queue
+
+import (
+	"container/list"
+	"fmt"
+	"strings"
+)
+
+// LinkedListStack 基于链表实现的栈, 使用内置包 list 来实现栈
+type LinkedListStack struct {
+	list *list.List
+}
+
+// NewLinkedListStack 初始化链表
+func NewLinkedListStack() *LinkedListStack {
+	return &LinkedListStack{
+		list: list.New(),
+	}
+}
+
+// Push 入栈
+func (s *LinkedListStack) Push(value int) {
+	s.list.PushBack(value)
+}
+
+// Pop 出栈
+func (s *LinkedListStack) Pop() any {
+	if s.IsEmpty() {
+		return nil
+	}
+	e := s.list.Back()
+	s.list.Remove(e)
+	return e.Value
+}
+
+// Peek 访问栈顶元素
+func (s *LinkedListStack) Peek() any {
+	if s.IsEmpty() {
+		return nil
+	}
+	e := s.list.Back()
+	return e.Value
+}
+
+// Size 获取栈的长度
+func (s *LinkedListStack) Size() int {
+	return s.list.Len()
+}
+
+// IsEmpty 判断栈是否为空
+func (s *LinkedListStack) IsEmpty() bool {
+	return s.list.Len() == 0
+}
+
+func (s *LinkedListStack) Print() {
+	fmt.Println(s.toString())
+}
+
+func (s *LinkedListStack) toString() string {
+	var builder strings.Builder
+	if s.IsEmpty() {
+		fmt.Println("empty stack")
+	}
+	e := s.list.Back()
+	// 强转为 string, 会影响效率
+	str := fmt.Sprintf("%v", e.Value)
+	for e.Prev() != nil {
+		builder.WriteString(str + " -> ")
+		e = e.Prev()
+		str = fmt.Sprintf("%v", e.Value)
+	}
+	builder.WriteString(str)
+	return builder.String()
+}
diff --git a/codes/go/chapter_stack_and_queue/queue.go b/codes/go/chapter_stack_and_queue/queue.go
new file mode 100644
index 0000000..03b97e5
--- /dev/null
+++ b/codes/go/chapter_stack_and_queue/queue.go
@@ -0,0 +1,20 @@
+// File: queue.go
+// Created Time: 2022-11-29
+// Author: Reanon (793584285@qq.com)
+
+package chapter_stack_and_queue
+
+type Queue interface {
+	// Offer 元素入队
+	Offer(num any)
+	// Peek 访问首元素
+	Peek() any
+	// Poll 元素出队
+	Poll() 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
+}
diff --git a/codes/go/chapter_stack_and_queue/queue_test.go b/codes/go/chapter_stack_and_queue/queue_test.go
new file mode 100644
index 0000000..e8c74ec
--- /dev/null
+++ b/codes/go/chapter_stack_and_queue/queue_test.go
@@ -0,0 +1,93 @@
+// File: queue_test.go
+// Created Time: 2022-11-28
+// Author: Reanon (793584285@qq.com)
+
+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
+	queue = NewArrayQueue(capacity)
+
+	// 元素入队
+	queue.Offer(1)
+	queue.Offer(2)
+	queue.Offer(3)
+	queue.Offer(4)
+	queue.Offer(5)
+	t.Log("队列 queue = ", queue.toString())
+
+	// 访问队首元素
+	peek := queue.Peek()
+	t.Log("队首元素 peek = ", peek)
+
+	// 元素出队
+	pop := queue.Poll()
+	t.Log("出队元素 pop  = ", pop, ", 出队后 queue =", queue.toString())
+
+	// 获取队的长度
+	size := queue.Size()
+	t.Log("队的长度 size = ", size)
+
+	// 判断是否为空
+	isEmpty := queue.IsEmpty()
+	t.Log("队是否为空 = ", isEmpty)
+}
+
+func TestLinkedListQueue(t *testing.T) {
+	// 初始化队
+	var queue Queue
+	queue = NewLinkedListQueue()
+
+	// 元素入队
+	queue.Offer(1)
+	queue.Offer(2)
+	queue.Offer(3)
+	queue.Offer(4)
+	queue.Offer(5)
+	t.Log("队列 queue = ", queue.toString())
+
+	// 访问队首元素
+	peek := queue.Peek()
+	t.Log("队首元素 peek = ", peek)
+
+	// 元素出队
+	pop := queue.Poll()
+	t.Log("出队元素 pop  = ", pop, ", 出队后 queue =", queue.toString())
+
+	// 获取队的长度
+	size := queue.Size()
+	t.Log("队的长度 size = ", size)
+
+	// 判断是否为空
+	isEmpty := queue.IsEmpty()
+	t.Log("队是否为空 = ", isEmpty)
+}
+
+// BenchmarkArrayQueue 8 ns/op in Mac M1 Pro
+func BenchmarkArrayQueue(b *testing.B) {
+	capacity := 1000
+	stack := NewArrayQueue(capacity)
+	// use b.N for looping
+	for i := 0; i < b.N; i++ {
+		stack.Offer(777)
+	}
+	for i := 0; i < b.N; i++ {
+		stack.Poll()
+	}
+}
+
+// BenchmarkLinkedQueue 62.66 ns/op in Mac M1 Pro
+func BenchmarkLinkedQueue(b *testing.B) {
+	stack := NewLinkedListQueue()
+	// use b.N for looping
+	for i := 0; i < b.N; i++ {
+		stack.Offer(777)
+	}
+	for i := 0; i < b.N; i++ {
+		stack.Poll()
+	}
+}
diff --git a/codes/go/chapter_stack_and_queue/stack.go b/codes/go/chapter_stack_and_queue/stack.go
new file mode 100644
index 0000000..7795387
--- /dev/null
+++ b/codes/go/chapter_stack_and_queue/stack.go
@@ -0,0 +1,20 @@
+// File: stack.go
+// Created Time: 2022-11-26
+// Author: Reanon (793584285@qq.com)
+
+package chapter_stack_and_queue
+
+type Stack interface {
+	// Push 元素入栈
+	Push(num int)
+	// Peek 访问栈顶元素
+	Peek() any
+	// Pop 元素出栈
+	Pop() any
+	// Size 栈的长度
+	Size() int
+	// IsEmpty 栈是否为空
+	IsEmpty() bool
+	// toString 栈输出为字符串
+	toString() string
+}
diff --git a/codes/go/chapter_stack_and_queue/stack_test.go b/codes/go/chapter_stack_and_queue/stack_test.go
new file mode 100644
index 0000000..95c6d24
--- /dev/null
+++ b/codes/go/chapter_stack_and_queue/stack_test.go
@@ -0,0 +1,90 @@
+// File: stack_test.go
+// Created Time: 2022-11-28
+// Author: Reanon (793584285@qq.com)
+
+package chapter_stack_and_queue
+
+import "testing"
+
+func TestArrayStack(t *testing.T) {
+	// 初始化栈, 使用接口承接
+	var stack Stack
+	stack = NewArrayStack()
+
+	// 元素入栈
+	stack.Push(1)
+	stack.Push(2)
+	stack.Push(3)
+	stack.Push(4)
+	stack.Push(5)
+	t.Log("栈 stack = ", stack.toString())
+
+	// 访问栈顶元素
+	peek := stack.Peek()
+	t.Log("栈顶元素 peek = ", peek)
+
+	// 元素出栈
+	pop := stack.Pop()
+	t.Log("出栈元素 pop  = ", pop, ", 出栈后 stack =", stack.toString())
+
+	// 获取栈的长度
+	size := stack.Size()
+	t.Log("栈的长度 size = ", size)
+
+	// 判断是否为空
+	isEmpty := stack.IsEmpty()
+	t.Log("栈是否为空 = ", isEmpty)
+}
+
+func TestLinkedListStack(t *testing.T) {
+	// 初始化栈
+	var stack Stack
+	stack = NewLinkedListStack()
+	// 元素入栈
+	stack.Push(1)
+	stack.Push(2)
+	stack.Push(3)
+	stack.Push(4)
+	stack.Push(5)
+	t.Log("栈 stack = ", stack.toString())
+
+	// 访问栈顶元素
+	peek := stack.Peek()
+	t.Log("栈顶元素 peek = ", peek)
+
+	// 元素出栈
+	pop := stack.Pop()
+	t.Log("出栈元素 pop  = ", pop, ", 出栈后 stack =", stack.toString())
+
+	// 获取栈的长度
+	size := stack.Size()
+	t.Log("栈的长度 size = ", size)
+
+	// 判断是否为空
+	isEmpty := stack.IsEmpty()
+	t.Log("栈是否为空 = ", isEmpty)
+}
+
+// BenchmarkArrayStack 8 ns/op in Mac M1 Pro
+func BenchmarkArrayStack(b *testing.B) {
+	stack := NewArrayStack()
+	// use b.N for looping
+	for i := 0; i < b.N; i++ {
+		stack.Push(777)
+	}
+	for i := 0; i < b.N; i++ {
+		stack.Pop()
+	}
+}
+
+// BenchmarkLinkedListStack 65.02 ns/op in Mac M1 Pro
+func BenchmarkLinkedListStack(b *testing.B) {
+	stack := NewLinkedListStack()
+	// use b.N for looping
+	for i := 0; i < b.N; i++ {
+		stack.Push(777)
+	}
+	for i := 0; i < b.N; i++ {
+		stack.Pop()
+	}
+}
diff --git a/codes/go/chapter_tree/binary_search_tree.go b/codes/go/chapter_tree/binary_search_tree.go
index 26eb94d..ac14e79 100644
--- a/codes/go/chapter_tree/binary_search_tree.go
+++ b/codes/go/chapter_tree/binary_search_tree.go
@@ -5,8 +5,9 @@
 package chapter_tree
 
 import (
-	. "github.com/krahets/hello-algo/pkg"
 	"sort"
+
+	. "github.com/krahets/hello-algo/pkg"
 )
 
 type BinarySearchTree struct {
diff --git a/codes/go/chapter_tree/binary_tree_bfs.go b/codes/go/chapter_tree/binary_tree_bfs.go
index d04102f..5c07a96 100644
--- a/codes/go/chapter_tree/binary_tree_bfs.go
+++ b/codes/go/chapter_tree/binary_tree_bfs.go
@@ -6,6 +6,7 @@ package chapter_tree
 
 import (
 	"container/list"
+
 	. "github.com/krahets/hello-algo/pkg"
 )
 
diff --git a/codes/go/chapter_tree/binary_tree_test.go b/codes/go/chapter_tree/binary_tree_test.go
index 2c05076..03a8553 100644
--- a/codes/go/chapter_tree/binary_tree_test.go
+++ b/codes/go/chapter_tree/binary_tree_test.go
@@ -5,8 +5,9 @@
 package chapter_tree
 
 import (
-	. "github.com/krahets/hello-algo/pkg"
 	"testing"
+
+	. "github.com/krahets/hello-algo/pkg"
 )
 
 func TestBinaryTree(t *testing.T) {