2023-01-11 23:48:10 +08:00
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/**
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* File: queue.swift
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* Created Time: 2023-01-11
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* Author: nuomi1 (nuomi1@qq.com)
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*/
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@main
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enum Queue {
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/* Driver Code */
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static func main() {
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/* 初始化队列 */
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// Swift 没有内置的队列类，可以把 Array 当作队列来使用
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var queue: [Int] = []
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/* 元素入队 */
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queue.append(1)
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queue.append(3)
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queue.append(2)
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queue.append(5)
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queue.append(4)
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print("队列 queue = \(queue)")
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/* 访问队首元素 */
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let peek = queue.first!
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print("队首元素 peek = \(peek)")
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/* 元素出队 */
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2023-03-13 21:58:21 +08:00
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// 使用 Array 模拟时 pop 的复杂度为 O(n)
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2023-01-11 23:48:10 +08:00
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let pool = queue.removeFirst()
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2023-03-13 21:58:21 +08:00
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print("出队元素 pop = \(pool)，出队后 queue = \(queue)")
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2023-01-11 23:48:10 +08:00
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/* 获取队列的长度 */
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let size = queue.count
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print("队列长度 size = \(size)")
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/* 判断队列是否为空 */
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let isEmpty = queue.isEmpty
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print("队列是否为空 = \(isEmpty)")
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}
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}
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