{"id":10867,"date":"2019-01-10T17:57:45","date_gmt":"2019-01-10T17:57:45","guid":{"rendered":"http:\/\/www.softwareeverydayblog.com\/?p=10867"},"modified":"2019-01-10T18:57:28","modified_gmt":"2019-01-10T18:57:28","slug":"hackerrank-pairs","status":"publish","type":"post","link":"https:\/\/www.softwareeverydayblog.com\/?p=10867","title":{"rendered":"[Hackerrank] Pairs"},"content":{"rendered":"<p>You will be given an array of integers and a target value. Determine the number of pairs of array elements that have a difference equal to a target value.<\/p>\n<p>[<a href=\"https:\/\/www.hackerrank.com\/challenges\/pairs\/problem\" rel=\"noopener\" target=\"_blank\">Problem Link<\/a>]<\/p>\n<ul>\n<li>Add all elements to a Set<\/li>\n<li>To figure if an element arr[i] and some X make a pair, we check if<br \/>\n(arr[i] &#8211; Target) is in Set<\/p>\n<p><strong>why?<\/strong><br \/>\narr[i] &#8211; X = Target<br \/>\nX = arr[i] &#8211; Target<\/li>\n<\/ul>\n<pre lang=\"java\">\r\n    \/\/ Complete the pairs function below.\r\n    static int pairs(int k, int[] arr) {\r\n        Set<Integer> arrSet = new HashSet<Integer>();\r\n        for ( int i = 0 ; i < arr.length ; i++ )\r\n            arrSet.add(arr[i]);\r\n\r\n        int ret = 0;\r\n        for ( int i = 0 ; i < arr.length ; i++ )\r\n            if (arrSet.contains(arr[i]-k))\r\n                ret++;\r\n        return ret;\r\n    }\r\n<\/pre>\n","protected":false},"excerpt":{"rendered":"<p>You will be given an array of integers and a target value. Determine the number of pairs of array elements that have a difference equal to a target value. [Problem Link] Add all elements to a Set To figure if an element arr[i] and some X make a pair, we check if (arr[i] &#8211; Target) [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-10867","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/www.softwareeverydayblog.com\/index.php?rest_route=\/wp\/v2\/posts\/10867","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.softwareeverydayblog.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.softwareeverydayblog.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.softwareeverydayblog.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.softwareeverydayblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=10867"}],"version-history":[{"count":3,"href":"https:\/\/www.softwareeverydayblog.com\/index.php?rest_route=\/wp\/v2\/posts\/10867\/revisions"}],"predecessor-version":[{"id":10869,"href":"https:\/\/www.softwareeverydayblog.com\/index.php?rest_route=\/wp\/v2\/posts\/10867\/revisions\/10869"}],"wp:attachment":[{"href":"https:\/\/www.softwareeverydayblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=10867"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.softwareeverydayblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=10867"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.softwareeverydayblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=10867"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}