{"id":8117,"date":"2022-10-01T23:10:00","date_gmt":"2022-10-01T17:40:00","guid":{"rendered":"https:\/\/www.codingbroz.com\/?p=8117"},"modified":"2022-11-26T18:34:11","modified_gmt":"2022-11-26T13:04:11","slug":"maximum-palindromes-hackerrank-solution","status":"publish","type":"post","link":"https:\/\/www.codingbroz.com\/maximum-palindromes-hackerrank-solution\/","title":{"rendered":"Maximum Palindromes &#8211; HackerRank Solution"},"content":{"rendered":"\n<p>In this post, we will solve <strong>Maximum Palindromes HackerRank Solution<\/strong>. This problem <strong>(Maximum Palindromes)<\/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-663613d96a25a\" 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-663613d96a25a\" 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\/maximum-palindromes-hackerrank-solution\/#Solution_%E2%80%93_Maximum_Palindromes_%E2%80%93_HackerRank_Solution\" title=\"Solution &#8211; Maximum Palindromes &#8211; HackerRank Solution\">Solution &#8211; Maximum Palindromes &#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\/maximum-palindromes-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\/maximum-palindromes-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\/maximum-palindromes-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_Maximum_Palindromes_%E2%80%93_HackerRank_Solution\"><\/span><strong>Solution &#8211; Maximum Palindromes &#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;bits\/stdc++.h>\n\nusing namespace std;\n\n\n# define N 1000000007\n\nlong long int power(long long int a, long long int b, long long int c)\n{\n    if(b==0)\n    {\n        return 1;\n    }\n\n    long long int p = power(a,b\/2,c)%c;\n    p= (p*p) % c;\n\n    return (b%2==0)? p:(a*p)%c;\n\n}\n\nint main()\n{\n    int testcase;\n    string str;\n    int length;\n\n    \n\n    cin>>str;\n    cin>>testcase;\n\n    length= str.length();\n\n    long long int fact[length+1], inverse[length+1];\/\/modular multiplicaive inverse\n    fact[0]=1;\n    inverse[0]=1;\n\n    \/\/calculating factorial and inverse first as we can direct use them later\n    for(int i=1; i&lt;=length; i++)\n    {\n        fact[i]=(fact[i-1]*i) % N;\n        inverse[i]= power(fact[i],N-2,N); \/\/ calculating modular multiplicative inve using fermats little theroem\n    }\n\n\n    \/\/creating a 2d array where first index would store indexes and second would store freq of characters in the given string\n    int freq[length+1][26];\n\n    memset(freq,0, sizeof(freq)); \/\/ this will initialize all the values to the zero\n\n    for (int i = 1; i &lt;=length; ++i)\n    {\n        freq[i][str[i-1]-'a']++;\n\n    }\n\n    for (int i = 2; i &lt;=length; ++i)\n    {\n        for (int j = 0; j &lt; 26; ++j)\n        {\n            freq[i][j]+=freq[i-1][j];\n        }\n    }\n\n    \/\/this will accumlate the freq on chars to the desired point\n\n    \/\/ now in the que we need to get no of chars and their frequencies in the l -r region so we can use PnC\n\n    while(testcase--)\n    {\n        int l,r;\n        cin>>l>>r;\n        long long int deno=1;\/\/denominator\n        long long int nume=0;\/\/numerator\n        int value=0;\n        int odd=0;\n        int even=0;\n\n        for (int i = 0; i &lt; 26; ++i)\n        {\n            value=freq[r][i]-freq[l-1][i];\n\n            if(value%2!=0)\n            {\n                odd++;\n            }\n\n            even+=value\/2;\n            \/\/here we are getting odd and even count which can the be used in PNC if its even we need to devide by that fact;\n\n            deno=( (deno*inverse[value\/2])%N);\n            \/\/cout&lt;&lt;\"value   \"&lt;&lt;value&lt;&lt;endl;\n            \/\/cout&lt;&lt;deno&lt;&lt;endl;\n\n        }\n\n        nume= fact[even];\n        long long int res= (nume*deno)%N;\n        if(odd)\n        {\n            res=(res*odd)%N ;\n        }\n\n            cout&lt;&lt;res&lt;&lt;endl;\n    }\n\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=\"\">import math\nimport os\nimport random\nimport re\nimport sys\nfrom collections import Counter, defaultdict\nfrom math import factorial\n\nfact = dict()\npowr = dict()\ndist = defaultdict(lambda : Counter(\"\"))\n\nm = 10 ** 9 + 7\n\ndef initialize(s):\n    fact[0], powr[0], dist[0] = 1, 1, Counter(s[0])\n    for j in range(1, len(s)):\n        fact[j] = (j * fact[j - 1]) % m\n        dist[j] = dist[j-1] + Counter(s[j])\n\ndef power(x, n, m):\n    if n == 1:\n        return x % m\n    elif n % 2 == 0:\n        return power(x ** 2 % m, n \/\/ 2, m)\n    else:\n        return (x * power(x ** 2 % m, (n - 1) \/\/ 2, m)) % m\n\n\ndef answerQuery(s, l, r):\n    # Return the answer for this query modulo 1000000007.\n    b = dist[r-1] - dist[l-2]\n    p, count, value = 0, 0, 1\n    for c in b.values():\n        if c >= 2:\n            count += c \/\/ 2\n            value = (value * fact[c \/\/ 2]) % m\n        if c % 2 == 1:\n            p += 1\n    return (max(1, p) * fact[count] * power(value, m - 2, m)) % m\n\nif __name__ == '__main__':\n    fptr = open(os.environ['OUTPUT_PATH'], 'w')\n\n    s = input()\n\n    initialize(s)\n    \n    print(dist)\n    q = int(input().strip())\n\n    for q_itr in range(q):\n        first_multiple_input = input().rstrip().split()\n\n        l = int(first_multiple_input[0])\n\n        r = int(first_multiple_input[1])\n\n        result = answerQuery(s,l, r)\n\n        fptr.write(str(result) + '\\n')\n\n    fptr.close()\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.math.*;\nimport java.security.*;\nimport java.text.*;\nimport java.util.*;\nimport java.util.concurrent.*;\nimport java.util.regex.*;\n\npublic class Solution {\n\n    private static final long MOD = 1000000007;\n\n\n    public static void main(String[] args) throws IOException {\n\n\n        FastReader sc = new FastReader(System.in);\n        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));\n        String s = sc.next();\n\/\/        long start = System.currentTimeMillis();\n        long[] factorials = new long[100002];\n        long[] reversed = new long[50002];\n        factorials[0] = 1;\n        for (int i = 1; i &lt; factorials.length; i++) {\n            factorials[i] = (factorials[i - 1] * i) % MOD;\n            if (i &lt; reversed.length) {\n                reversed[i] = reverse(factorials[i]);\n            }\n        }\n        int[][] chars = new int[s.length() + 1][26];\n        for (int i = 1; i &lt;= s.length(); i++) {\n            for (int j = 0; j &lt; 26; j++) {\n                chars[i][j] += chars[i - 1][j];\n            }\n            chars[i][s.charAt(i - 1) - 'a']++;\n        }\n        int q = sc.nextInt();\n        for (int i = 0; i &lt; q; i++) {\n            int l = sc.nextInt();\n            int r = sc.nextInt();\n            int[] qchars = new int[26];\n            int oddCount = 0;\n            int palindromeMain = 0;\n            long result = 1;\n            for (int j = 0; j &lt; 26; j++) {\n                qchars[j] = chars[r][j] - chars[l - 1][j];\n                if (qchars[j] % 2 == 1) {\n                    oddCount++;\n                }\n                int t = qchars[j] \/ 2;\n                palindromeMain += t;\n                if (t > 0) {\n\/\/                    result *= reverse(factorials[t]);\n                    result *= reversed[t];\n                    result %= MOD;\n                }\n            }\n            result *= factorials[palindromeMain];\n            result %= MOD;\n            if (oddCount > 0) {\n                result *= oddCount;\n                result %= MOD;\n            }\n            bw.write(String.valueOf(result));\n            bw.newLine();\n        }\n\/\/        bw.write(\"Execution time: \" + (System.currentTimeMillis() - start) + \" ms\");\n        bw.flush();\n        bw.close();\n    }\n\n    private static long reverse(long a) {\n        return BigInteger.valueOf(a).modPow(BigInteger.valueOf(MOD - 2L), BigInteger.valueOf(MOD)).longValue();\n\/\/        return BigInteger.valueOf(a).modInverse(BigInteger.valueOf(MOD)).longValue();\n    }\n\n    private static class FastReader {\n\n        private final BufferedReader br;\n\n        private StringTokenizer st;\n\n        public FastReader(InputStream is) {\n            br = new BufferedReader(new InputStreamReader(is));\n        }\n\n        public String next() throws IOException {\n            if (st == null || !st.hasMoreTokens()) {\n                st = new StringTokenizer(br.readLine());\n            }\n            return st.nextToken();\n        }\n\n        public int nextInt() throws IOException {\n            return Integer.parseInt(next());\n        }\n    }\n}\n<\/pre>\n\n\n\n<p><strong>Note:<\/strong> This problem <strong>(<a href=\"https:\/\/www.hackerrank.com\/challenges\/maximum-palindromes\/problem\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">Maximum Palindromes<\/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 Maximum Palindromes HackerRank Solution. This problem (Maximum Palindromes) 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\/8117"}],"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=8117"}],"version-history":[{"count":4,"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/posts\/8117\/revisions"}],"predecessor-version":[{"id":8365,"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/posts\/8117\/revisions\/8365"}],"wp:attachment":[{"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/media?parent=8117"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/categories?post=8117"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/tags?post=8117"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}