投稿時間:2023-07-22 13:09:17 RSSフィード2023-07-22 13:00 分まとめ(9件)

カテゴリー等	サイト名等	記事タイトル・トレンドワード等	リンクURL	頻出ワード・要約等/検索ボリューム	登録日
IT	気になる、記になる…	Twitter、非認証アカウントのDMの送信数を制限 ｰ Twitter Blueへの加入を推奨	https://taisy0.com/2023/07/22/174351.html	twitter	2023-07-22 03:02:03
TECH	Techable（テッカブル）	動画マーケティングツール「1ROLL」、字幕自動生成・動画要約など“生成AI”機能追加	https://techable.jp/archives/214842	動画配信	2023-07-22 03:00:46
Google	カグア！Google Analytics 活用塾:事例や使い方	音声配信大手stand.fmで長時間に渡りシステム障害中	https://www.kagua.biz/marke/podcast/20230722a1.html	standfm	2023-07-22 03:29:14
AWS	AWS Japan Blog	CloudWatch Synthetics の Canary を大規模に管理する	https://aws.amazon.com/jp/blogs/news/managing-cloudwatch-synthetics-canaries-at-scale/	CloudWatchSyntheticsのCanaryを大規模に管理するAmazonCloudWatchSyntheticsでは、アプリケーションエンドポイント、RESTAPI、ウェブサイトコンテンツのパフォーマンスと可用性を自動的に監視できるため、顧客よりも先に問題を発見できます。	2023-07-22 03:19:59
js	JavaScriptタグが付けられた新着投稿 - Qiita	javascript async関数について	https://qiita.com/neoanti1/items/7c915a639f497710c874	async	2023-07-22 12:56:58
AWS	AWSタグが付けられた新着投稿 - Qiita	AWS Amazon Linux 2023 に MySQL 導入	https://qiita.com/kutinasi_hobby/items/aecc58123d4f8fb4ca22	amazonlinuxmysqlec	2023-07-22 12:56:58
海外TECH	DEV Community	Array Strengths, Weaknesses, and Big-O Complexity Analysis	https://dev.to/ggorantala/array-strengths-weaknesses-and-big-o-complexity-analysis-4aho	Array Strengths Weaknesses and Big O Complexity AnalysisRead about Array Data Structures article before reading through this article Arrays are fundamental data structures in computer science and programming offering a range of strengths weaknesses and Big O complexities that impact their efficiency and usability Understanding the characteristics of arrays is crucial for choosing the right data structure for specific tasks and optimizing program performance In this article we delve into arrays strengths weaknesses and Big O complexities We explore the benefits arrays provide such as random and sequential access simplicity of implementation and cache friendliness Simultaneously we address their limitations including a fixed size insertion and deletion operations challenges and inflexibility Additionally we discuss the time complexities associated with common array operations such as access search insertion deletion and resizing By gaining insights into these aspects programmers can make informed decisions when utilizing arrays and effectively balance trade offs between efficiency and functionality in their applications StrengthsThere are many advantages to using arrays some of which are outlined below Fast lookups random access Fast appendsSimple implementationCache friendliness Fast lookups Random access Retrieving the element at a given index takes O time regardless of the array s length For example int A The array has five elements and the length of the array is calculated using A length which is As arrays are zero indexed the last element is accessed using A A length which is A as shown in the following sketch If we access array elements using the index like A or A it takes a single unit of time or in big o terms constant operation A A A A Index out of bounds exception as there is no A value All of the above operations consume a single unit of time which is O time Fast appendsAdding a new element at the end of the array takes O time if the array has space Let us create an array with a capacity and insert values and at indexes and The following code explains it int A new int A A Now if we were to insert a new value into the array we could do A Which inserts value at the index This operation consumes a single unit of time which is constant This is the reason the appends at the end are fast Enough talk Here is a simple algorithm that creates an array with a size and inserts values into the array Finally we insert an element at the array length import java util Arrays public class ArrayAppends public static void main String args int A new int int currentLength Let us add elements to the array for int i i lt i A i i currentLength when i length is set to System out println Arrays toString A System out println current array items length currentLength System out println Array capacity A length System out println Element insert at end Arrays toString insertAtEnd A currentLength Inserting element at the end public static int insertAtEnd int A int currentLength A currentLength return A Outputs current array items length Array capacity Element insert at end Simple ImplementationArrays have a straightforward implementation in most programming languages making them easy to understand and use Cache FriendlinessElements in an array are stored contiguously in memory which improves cache performance and can lead to faster access times WeaknessesThere are some dis advantages of using arrays some of which are outlined below Fixed size Memory unused or wasted Size doubling Costly insertsCostly deletes Fixed sizeArrays have a fixed size defined at the time of creation Adding or removing elements beyond the initial size requires creating a new array and copying the existing elements which can be inefficient You need to specify how many elements you will store in your array ahead of time Unless you re using a fancy dynamic array int A new int contains elements Memory unused or wastedIf an array s size is larger than the number of elements it contains memory is wasted Imagine an array with a capacity of We have two elements to store in this array and then we are wasting three unfilled cells and a waste of memory which means bytes bytes of memory is wasted integer takes bytes Size doublingLet us consider an array with a capacity of elements But the elements we want to store in this array are more which means we have to double the size create a new array copy the old array elements and add new elements The time complexity is O n You will learn how to double the array size in the next lessons Costly insertsInserting appending an element at the end of the array takes O time We have seen this in the strengths fast appends But inserting an element at the start middle of the array takes O n time Why If we want to insert something into an array first we have to make space by scooting over everything starting at the index we re inserting into as shown in the image In the worst case we re inserting into the th index in the array prepending so we have to scoot over everything That s O n time Inserting an element at the nd index and moving the rest of the element right shift each once The resultant array becomes A B C D E In the next lessons you will learn more about insertion and shifting algorithms with clear explanations code snippets and sketches to understand why these inserts are expensive at the start and middle Costly deletesDeleting an element at the end of the array takes O time which is the best case In computer science we only care about the worse case scenarios when working on algorithms But when we remove an element from the middle or start of the array we have to fill the gap by scooting over all the elements after it This will be O n if we consider a case of deleting an element from the th index Deleting an element at the rd index and filling the gap by left shifting the rest of the elements the resultant array becomes A B C D E Big O Complexities Operation Complexity Explanation Lookup Access a value at a given index O Accessing an element by its index is a constant time operation Search an element in an array O N Searching for a specific element in an unsorted array requires iterating through each element in the worst case Update a value at a given index O Updating any element at any given index is always constant time Insert at the beginning middle O N Inserting an element at the beginning or middle of the array requires shifting the existing elements resulting in a linear time complexity Append at the end O If the array has space available inserting an element at the end takes constant time Delete at the beginning middle O N Deleting an element from the beginning or middle of the array requires shifting the remaining elements resulting in a linear time complexity Delete at the end O Deleting the last element of an array can be done in constant time Resize array O N Resizing an array requires creating a new array and copying the existing elements which takes linear time The the Big O complexities mentioned above are for basic operations and assume an unsorted array Some specialized data structures such as Heaps or HashTable s can provide more efficient alternatives for specific use cases In the next lessons you will learn more about array capacity vs length insertions and deletion algorithms They are the simplest yet most powerful and helps you when working on array problems	2023-07-22 03:25:06
海外科学	NYT > Science	Tornado Rips Through North Carolina Pfizer Site, Damaging Drug Supplies	https://www.nytimes.com/2023/07/20/health/tornado-pfizer-drug-shortage.html	Tornado Rips Through North Carolina Pfizer Site Damaging Drug SuppliesExtensive damage occurred at the company s property in Rocky Mount and many products used by hospitals appeared to have been affected This could further exacerbate shortages	2023-07-22 03:15:20
ニュース	BBC News - Home	USA 3-0 Vietnam: Sophia Smith scores twice as defending champions win World Cup opener	https://www.bbc.co.uk/sport/football/66275965?at_medium=RSS&at_campaign=KARANGA	USA Vietnam Sophia Smith scores twice as defending champions win World Cup openerUnited States launch their bid for an unprecedented third consecutive world crown with a comfortable win against Women s World Cup debutants Vietnam in Auckland	2023-07-22 03:44:22