{"id":8209,"date":"2022-07-25T22:26:54","date_gmt":"2022-07-25T16:56:54","guid":{"rendered":"https:\/\/golangbyexamples.com\/?p=8209"},"modified":"2022-07-25T22:51:16","modified_gmt":"2022-07-25T17:21:16","slug":"number-double-golang","status":"publish","type":"post","link":"https:\/\/golangbyexamples.com\/number-double-golang\/","title":{"rendered":"Check If N and Its Double Exist in Go (Golang)"},"content":{"rendered":"\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_17 counter-hierarchy counter-decimal ez-toc-light-blue\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" style=\"display: none;\"><i class=\"ez-toc-glyphicon ez-toc-icon-toggle\"><\/i><\/a><\/span><\/div>\n<nav><ul class=\"ez-toc-list ez-toc-list-level-1\"><li class=\"ez-toc-page-1 ez-toc-heading-level-1\"><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/golangbyexamples.com\/number-double-golang\/#Overview\" title=\"Overview\">Overview<\/a><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-1\"><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/golangbyexamples.com\/number-double-golang\/#Program\" title=\"Program\">Program<\/a><\/li><\/ul><\/nav><\/div>\n<h1 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Overview\"><\/span><strong>Overview<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<p class=\"has-medium-font-size\">An array is given. The objective is to find if there exists any number for which it&#8217;s double also exists.<\/p>\n\n\n\n<p class=\"has-medium-font-size\"><strong>Example 1<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">Input: [8,5,4,3]\nOutput: true\nExplanation: 4 and 8<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\"><strong>Example 2<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">Input: [1,3,7,9]\nOutput: false\nExplanation: There exists no number for which its double exist<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">The idea is to use a map here. For every element, we will check&nbsp; and return true if<\/p>\n\n\n\n<ul class=\"has-medium-font-size wp-block-list\"><li>If its double exists in the map<\/li><\/ul>\n\n\n\n<ul class=\"has-medium-font-size wp-block-list\"><li>If the number is even then if its half exists in the map<\/li><\/ul>\n\n\n\n<h1 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Program\"><\/span><strong>Program<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<p class=\"has-medium-font-size\">Below is the program for the same<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">package main\n\nimport \"fmt\"\n\nfunc checkIfExist(arr []int) bool {\n\tnumMap := make(map[int]bool)\n\n\tfor i := 0; i < len(arr); i++ {\n\t\tif numMap[arr[i]*2] {\n\t\t\treturn true\n\t\t}\n\t\tif arr[i]%2 == 0 &#038;&#038; numMap[arr[i]\/2] {\n\t\t\treturn true\n\t\t}\n\t\tnumMap[arr[i]] = true\n\t}\n\treturn false\n}\n\nfunc main() {\n\toutput := checkIfExist([]int{8, 5, 4, 3})\n\tfmt.Println(output)\n\n\toutput = checkIfExist([]int{1, 3, 7, 9})\n\tfmt.Println(output)\n\n}<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\"><strong>Output:<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">true\nfalse<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\"><strong>Note: <\/strong>Check out our Golang Advanced Tutorial. The tutorials in this series are elaborative and we have tried to cover all concepts with examples. This tutorial is for those who are looking to gain expertise and a solid understanding of golang - <a href=\"https:\/\/golangbyexamples.com\/golang-comprehensive-tutorial\/\">Golang Advance Tutorial<\/a><\/p>\n\n\n\n<p class=\"has-medium-font-size\">Also if you are interested in understanding how all design patterns can be implemented in Golang. If yes, then this post is for you - <a href=\"https:\/\/golangbyexamples.com\/all-design-patterns-golang\/\">All Design Patterns Golang<\/a><\/p>\n\n\n\n<p class=\"has-medium-font-size\">Also, check out our system design tutorial series here - <a href=\"https:\/\/techbyexample.com\/system-design-questions\/\">System Design Tutorial Series<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Table of Contents OverviewProgram Overview An array is given. The objective is to find if there exists any number for which it&#8217;s double also exists. Example 1 Example 2 The idea is&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":"","footnotes":"","jetpack_publicize_message":"","jetpack_is_tweetstorm":false},"categories":[1],"tags":[3,4],"class_list":["post-8209","post","type-post","status-publish","format-standard","hentry","category-tech","tag-go","tag-golang"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v22.7 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Check If N and Its Double Exist in Go (Golang) - Welcome To Golang By Example<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/golangbyexamples.com\/number-double-golang\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Check If N and Its Double Exist in Go (Golang) - Welcome To Golang By Example\" \/>\n<meta property=\"og:description\" content=\"Table of Contents OverviewProgram Overview An array is given. 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