diff --git a/codes/go/chapter_stack_and_queue/array_deque.go b/codes/go/chapter_stack_and_queue/array_deque.go new file mode 100644 index 000000000..4df7493c9 --- /dev/null +++ b/codes/go/chapter_stack_and_queue/array_deque.go @@ -0,0 +1,115 @@ +// File: array_deque.go +// Created Time: 2023-03-13 +// Author: Reanon (793584285@qq.com) + +package chapter_stack_and_queue + +import "fmt" + +/* 基于环形数组实现的双向队列 */ +type arrayDeque struct { + nums []int // 用于存储双向队列元素的数组 + front int // 队首指针,指向队首元素 + queSize int // 双向队列长度 + queCapacity int // 队列容量(即最大容纳元素数量) +} + +/* 初始化队列 */ +func newArrayDeque(queCapacity int) *arrayDeque { + return &arrayDeque{ + nums: make([]int, queCapacity), + queCapacity: queCapacity, + front: 0, + queSize: 0, + } +} + +/* 获取双向队列的长度 */ +func (q *arrayDeque) size() int { + return q.queSize +} + +/* 判断双向队列是否为空 */ +func (q *arrayDeque) isEmpty() bool { + return q.queSize == 0 +} + +/* 计算环形数组索引 */ +func (q *arrayDeque) index(i int) int { + // 通过取余操作实现数组首尾相连 + // 当 i 越过数组尾部后,回到头部 + // 当 i 越过数组头部后,回到尾部 + return (i + q.queCapacity) % q.queCapacity +} + +/* 队首入队 */ +func (q *arrayDeque) pushFirst(num int) { + if q.queSize == q.queCapacity { + fmt.Println("双向队列已满") + return + } + // 队首指针向左移动一位 + // 通过取余操作,实现 front 越过数组头部后回到尾部 + q.front = q.index(q.front - 1) + // 将 num 添加至队首 + q.nums[q.front] = num + q.queSize++ +} + +/* 队尾入队 */ +func (q *arrayDeque) pushLast(num int) { + if q.queSize == q.queCapacity { + fmt.Println("双向队列已满") + return + } + // 计算尾指针,指向队尾索引 + 1 + rear := q.index(q.front + q.queSize) + // 将 num 添加至队首 + q.nums[rear] = num + q.queSize++ +} + +/* 队首出队 */ +func (q *arrayDeque) pollFirst() any { + num := q.peekFirst() + // 队首指针向后移动一位 + q.front = q.index(q.front + 1) + q.queSize-- + return num +} + +/* 队尾出队 */ +func (q *arrayDeque) pollLast() any { + num := q.peekLast() + q.queSize-- + return num +} + +/* 访问队首元素 */ +func (q *arrayDeque) peekFirst() any { + if q.isEmpty() { + return nil + } + return q.nums[q.front] +} + +/* 访问队尾元素 */ +func (q *arrayDeque) peekLast() any { + if q.isEmpty() { + return nil + } + // 计算尾元素索引 + last := q.index(q.front + q.queSize - 1) + return q.nums[last] +} + +/* 获取 Slice 用于打印 */ +func (q *arrayDeque) toSlice() []int { + // 仅转换有效长度范围内的列表元素 + res := make([]int, q.queSize) + for i, j := 0, q.front; i < q.queSize; i++ { + res[i] = q.nums[q.index(j)] + j++ + } + return res +} diff --git a/codes/go/chapter_stack_and_queue/deque_test.go b/codes/go/chapter_stack_and_queue/deque_test.go index 25deec25c..4353a7787 100644 --- a/codes/go/chapter_stack_and_queue/deque_test.go +++ b/codes/go/chapter_stack_and_queue/deque_test.go @@ -49,6 +49,49 @@ func TestDeque(t *testing.T) { fmt.Println("双向队列是否为空 =", isEmpty) } +func TestArrayDeque(t *testing.T) { + /* 初始化双向队列 */ + // 在 Go 中,将 list 作为双向队列使用 + deque := newArrayDeque(16) + + /* 元素入队 */ + deque.pushLast(3) + deque.pushLast(2) + deque.pushLast(5) + fmt.Print("双向队列 deque = ") + PrintSlice(deque.toSlice()) + + /* 访问元素 */ + peekFirst := deque.peekFirst() + fmt.Println("队首元素 peekFirst =", peekFirst) + peekLast := deque.peekLast() + fmt.Println("队尾元素 peekLast =", peekLast) + + /* 元素入队 */ + deque.pushLast(4) + fmt.Print("元素 4 队尾入队后 deque = ") + PrintSlice(deque.toSlice()) + deque.pushFirst(1) + fmt.Print("元素 1 队首入队后 deque = ") + PrintSlice(deque.toSlice()) + + /* 元素出队 */ + pollFirst := deque.pollFirst() + fmt.Print("队首出队元素 pollFirst = ", pollFirst, ",队首出队后 deque = ") + PrintSlice(deque.toSlice()) + pollLast := deque.pollLast() + fmt.Print("队尾出队元素 pollLast = ", pollLast, ",队尾出队后 deque = ") + PrintSlice(deque.toSlice()) + + /* 获取双向队列的长度 */ + size := deque.size() + fmt.Println("双向队列长度 size =", size) + + /* 判断双向队列是否为空 */ + isEmpty := deque.isEmpty() + fmt.Println("双向队列是否为空 =", isEmpty) +} + func TestLinkedListDeque(t *testing.T) { // 初始化队列 deque := newLinkedListDeque() @@ -85,7 +128,7 @@ func TestLinkedListDeque(t *testing.T) { fmt.Println("队是否为空 =", isEmpty) } -// BenchmarkArrayQueue 67.92 ns/op in Mac M1 Pro +// BenchmarkLinkedListDeque 67.92 ns/op in Mac M1 Pro func BenchmarkLinkedListDeque(b *testing.B) { deque := newLinkedListDeque() // use b.N for looping