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f68bbb0d59
* Revised the book * Update the book with the second revised edition * Revise base on the manuscript of the first edition
74 lines
1.7 KiB
Go
74 lines
1.7 KiB
Go
// File: array_queue.go
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// Created Time: 2022-11-28
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// Author: Reanon (793584285@qq.com)
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package chapter_stack_and_queue
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/* 基于环形数组实现的队列 */
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type arrayQueue struct {
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nums []int // 用于存储队列元素的数组
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front int // 队首指针,指向队首元素
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queSize int // 队列长度
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queCapacity int // 队列容量(即最大容纳元素数量)
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}
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/* 初始化队列 */
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func newArrayQueue(queCapacity int) *arrayQueue {
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return &arrayQueue{
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nums: make([]int, queCapacity),
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queCapacity: queCapacity,
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front: 0,
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queSize: 0,
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}
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}
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/* 获取队列的长度 */
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func (q *arrayQueue) size() int {
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return q.queSize
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}
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/* 判断队列是否为空 */
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func (q *arrayQueue) isEmpty() bool {
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return q.queSize == 0
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}
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/* 入队 */
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func (q *arrayQueue) push(num int) {
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// 当 rear == queCapacity 表示队列已满
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if q.queSize == q.queCapacity {
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return
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}
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// 计算队尾指针,指向队尾索引 + 1
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// 通过取余操作实现 rear 越过数组尾部后回到头部
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rear := (q.front + q.queSize) % q.queCapacity
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// 将 num 添加至队尾
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q.nums[rear] = num
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q.queSize++
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}
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/* 出队 */
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func (q *arrayQueue) pop() any {
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num := q.peek()
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// 队首指针向后移动一位,若越过尾部,则返回到数组头部
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q.front = (q.front + 1) % q.queCapacity
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q.queSize--
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return num
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}
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/* 访问队首元素 */
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func (q *arrayQueue) peek() any {
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if q.isEmpty() {
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return nil
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}
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return q.nums[q.front]
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}
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/* 获取 Slice 用于打印 */
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func (q *arrayQueue) toSlice() []int {
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rear := (q.front + q.queSize)
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if rear >= q.queCapacity {
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rear %= q.queCapacity
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return append(q.nums[q.front:], q.nums[:rear]...)
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}
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return q.nums[q.front:rear]
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}
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