{"id":7964,"date":"2022-09-23T23:10:00","date_gmt":"2022-09-23T17:40:00","guid":{"rendered":"https:\/\/www.codingbroz.com\/?p=7964"},"modified":"2022-12-09T15:13:31","modified_gmt":"2022-12-09T09:43:31","slug":"fraudulent-activity-notifications-hackerrank-solution","status":"publish","type":"post","link":"https:\/\/www.codingbroz.com\/fraudulent-activity-notifications-hackerrank-solution\/","title":{"rendered":"Fraudulent Activity Notifications &#8211; HackerRank Solution"},"content":{"rendered":"\n<p>In this post, we will solve <strong>Fraudulent Activity Notifications HackerRank Solution<\/strong>. This problem <strong>(Fraudulent Activity Notifications)<\/strong> is a part of <strong>HackerRank Problem Solving<\/strong> series.<\/p>\n\n\n\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_65 ez-toc-wrap-left counter-hierarchy ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<label for=\"ez-toc-cssicon-toggle-item-662d5e1ac54a2\" class=\"ez-toc-cssicon-toggle-label\"><label class=\"ez-toc-title\">Table of Contents<\/label>\n<span class=\"ez-toc-cssicon\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #0090ff;color:#0090ff\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #0090ff;color:#0090ff\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/label><input type=\"checkbox\"  id=\"ez-toc-cssicon-toggle-item-662d5e1ac54a2\" checked \/><nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.codingbroz.com\/fraudulent-activity-notifications-hackerrank-solution\/#Solution_%E2%80%93_Fraudulent_Activity_Notifications_%E2%80%93_HackerRank_Solution\" title=\"Solution &#8211; Fraudulent Activity Notifications &#8211; HackerRank Solution\">Solution &#8211; Fraudulent Activity Notifications &#8211; HackerRank Solution<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.codingbroz.com\/fraudulent-activity-notifications-hackerrank-solution\/#C\" title=\"C++\">C++<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.codingbroz.com\/fraudulent-activity-notifications-hackerrank-solution\/#Python\" title=\"Python\">Python<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.codingbroz.com\/fraudulent-activity-notifications-hackerrank-solution\/#Java\" title=\"Java\">Java<\/a><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Solution_%E2%80%93_Fraudulent_Activity_Notifications_%E2%80%93_HackerRank_Solution\"><\/span><strong>Solution &#8211; Fraudulent Activity Notifications &#8211; HackerRank Solution<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"C\"><\/span><strong>C++<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"cpp\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">#include &lt;iostream>\n#include &lt;cstdio>\n\nusing namespace std;\n\nint arr[200010];\nint temp_arr[200010];\nint counts[210];\n\nfloat get_median(int size) {\n    int index = 0;\n    for (int i = 0; i &lt; 210 ; i++) {\n        int count = counts[i];\n        while (count--) {\n            temp_arr[index++] = i;\n            if (index > size\/2) { break; }\n        }\n        if (index > size\/2) { break; }\n    }\n    return size % 2 == 1 ? temp_arr[size\/2] : (temp_arr[size\/2] + temp_arr[size\/2-1])\/2.0;\n}\n\nint main() {\n    int n, d;\n\n    scanf(\"%d %d\", &amp;n, &amp;d);\n    for (int i = 0; i &lt; n ; i++) {\n        scanf(\"%d\", &amp;arr[i]);\n    }\n\n    int alarm_count = 0;\n    float median = 210;\n\n    for (int i = 0; i &lt; d ; i++) {\n        counts[arr[i]]++;\n    }\n    median = get_median(d);\n\n    for (int i = d; i &lt; n; i++) {\n        if (arr[i] >= 2*median) {\n            alarm_count++;\n        }\n\n        \/\/ update counts array\n        counts[arr[i-d]]--;\n        counts[arr[i]]++;\n\n        median = get_median(d);\n    }\n\n    printf(\"%d\\n\", alarm_count);\n    return 0;\n}\n<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Python\"><\/span><strong>Python<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"python\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">#!\/bin\/python3\n\nimport sys\nimport bisect as bs\n\ndef index(a, x):\n    'Locate the leftmost value exactly equal to x'\n    i = bs.bisect_left(a, x)\n    if i != len(a) and a[i] == x:\n        return i\n    raise ValueError\n\ndef median(a_sorted, days):\n    half = len(a_sorted)\/\/2\n    \n    if days % 2:\n        median = a_sorted[half]\n    else:\n        median = (a_sorted[half-1] + a_sorted[half])\/2\n        \n    return float(median)\n\ndef activityNotifications(log, days):\n    heap = sorted(log[:days])\n    res = 0\n    med = 0\n    to_del = 0\n    \n    for ind in range(days, len(log)):\n        med = median(heap, days)\n        #print(\"heap: {}\".format(heap))\n        #print(\"log[{}] = {} med = {}\".format(ind, log[ind], med))\n            \n        if float(log[ind]) >= 2*med:\n            res += 1\n        \n        #del heap[heap.index(log[to_del])]\n        del heap[index(heap, log[to_del])]\n        bs.insort(heap, log[ind])\n        to_del += 1\n            \n    return res\n        \n\nif __name__ == \"__main__\":\n    n, d = input().strip().split(' ')\n    n, d = [int(n), int(d)]\n    expenditure = list(map(int, input().strip().split(' ')))\n    result = activityNotifications(expenditure, d)\n    print(result)\n<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Java\"><\/span><strong>Java<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"java\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">import java.io.*;\nimport java.util.*;\n\npublic class Solution {\n\n    public static void main(String[] args) {\n        Scanner input = new Scanner(System.in);\n        int n = input.nextInt();\n        int d = input.nextInt();\n        int notifications = 0;\n        Queue&lt;Integer> queue = new LinkedList&lt;>();\n        int[] pastActivity = new int[201];\n        \n        \/\/Wait for d transactions before any notifications\n        for(int i = 0; i &lt; d; i++)\n        {\n            int transaction = input.nextInt();\n            queue.offer(transaction);\n            pastActivity[transaction] = pastActivity[transaction]+1;\n        }\n            \n        for(int i = 0; i &lt; n-d; i++)\n        {\n            int newTransaction = input.nextInt();\n            \n            \/\/Check if fraudulent activity may have occurred\n            if(newTransaction >= (2* median(pastActivity, d)))\n                notifications++;\n                \n            \/\/Remove the oldest transaction\n            int oldestTransaction = queue.poll();\n            pastActivity[oldestTransaction] = pastActivity[oldestTransaction]-1;\n            \n            \/\/Add the new transaction\n            queue.offer(newTransaction);\n            pastActivity[newTransaction] = pastActivity[newTransaction]+1;\n        }\n        \n        System.out.println(notifications);\n    }\n    \n    static double median(int[] array, int elements)\n    {\n        int index = 0;\n        \n        if(elements % 2 == 0)\/\/Find median of even # of elements\n        {\n            int counter = (elements \/ 2);\n\n            while(counter > 0)\n            {                \n                counter -= array[index];\n                index++;\n            }\n            index--;\/\/Remove extra iteration\n            if(counter &lt;= -1)\/\/This index covers both medians\n                return index;\n            else\/\/(counter == 0) We need to find the next median index \n            {\n                int firstIndex = index;\n                int secondIndex = index+1;\n                while(array[secondIndex] == 0)\/\/Find next non-zero transaction\n                {\n                    secondIndex++;\n                }\n                return (double) (firstIndex + secondIndex) \/ 2.0;\/\/Calculate the average of middle two elements\n            }\n        }\n        else\/\/Find median of odd # of elements\n        {\n            int counter = (elements \/ 2);\n\n            while(counter >= 0)\n            {\n                counter -= array[index]; index++;\n            }\n            return (double) index-1;\n        }\n    }\n    \n    \n    static void printArray(int[] array)\n    {\n        System.out.println(\"Array\");\n        for(int i = 0; i &lt; array.length; i++)\n        {\n            if(array[i] > 0)\n                System.out.println(i+\" : \"+array[i]);\n        }\n    }\n}\n<\/pre>\n\n\n\n<p><strong>Note:<\/strong> This problem <strong>(<a href=\"https:\/\/www.hackerrank.com\/challenges\/fraudulent-activity-notifications\/problemhttps:\/\/www.hackerrank.com\/challenges\/fraudulent-activity-notifications\/problem\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">Fraudulent Activity Notifications<\/a>)<\/strong> is generated by <strong><a href=\"https:\/\/www.hackerrank.com\/\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">HackerRank<\/a><\/strong> but the solution is provided by <strong><a href=\"https:\/\/www.codingbroz.com\/\">CodingBroz<\/a><\/strong>. This tutorial is only for <strong>Educational<\/strong> and <strong>Learning<\/strong> purpose.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In this post, we will solve Fraudulent Activity Notifications HackerRank Solution. This problem (Fraudulent Activity Notifications) is a part of HackerRank Problem Solving series.<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""}},"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[9,190],"tags":[191],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/posts\/7964"}],"collection":[{"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/comments?post=7964"}],"version-history":[{"count":5,"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/posts\/7964\/revisions"}],"predecessor-version":[{"id":8417,"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/posts\/7964\/revisions\/8417"}],"wp:attachment":[{"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/media?parent=7964"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/categories?post=7964"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/tags?post=7964"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}