{"id":6245,"date":"2025-05-30T20:01:06","date_gmt":"2025-05-30T14:31:06","guid":{"rendered":"https:\/\/namastedev.com\/blog\/?p=6245"},"modified":"2025-05-30T20:01:06","modified_gmt":"2025-05-30T14:31:06","slug":"reverse-digits-of-an-integer","status":"publish","type":"post","link":"https:\/\/namastedev.com\/blog\/reverse-digits-of-an-integer\/","title":{"rendered":"Reverse Digits of an Integer"},"content":{"rendered":"\n<!-- Prism.js CSS and JS -->\n<link href=\"https:\/\/cdn.jsdelivr.net\/npm\/prismjs@1.29.0\/themes\/prism-tomorrow.css\" rel=\"stylesheet\" \/>\n<script src=\"https:\/\/cdn.jsdelivr.net\/npm\/prismjs@1.29.0\/prism.js\"><\/script>\n<script src=\"https:\/\/cdn.jsdelivr.net\/npm\/prismjs@1.29.0\/plugins\/autoloader\/prism-autoloader.min.js\"><\/script>\n\n\n<style>\n .wp_blog_code-tabs-container {\n   font-family: \"Segoe UI\", sans-serif !important;\n   max-width: 900px !important;\n   margin: 2rem auto !important;\n   border: 1px solid #ddd !important;\n   border-radius: 8px !important;\n   overflow: hidden !important;\n   background-color: white !important;\n }\n\n\n .wp_blog_code-tabs-header {\n   background: #f7f7f7 !important;\n   display: flex !important;\n   border-bottom: 1px solid #ddd !important;\n }\n\n\n .wp_blog_code-tab-button {\n   flex: 1 !important;\n   padding: 10px 15px !important;\n   border: none !important;\n   background: transparent !important;\n   cursor: pointer !important;\n   font-weight: bold !important;\n   transition: background 0.2s !important;\n   color: #242B33 !important;\n }\n\n\n .wp_blog_code-tab-button.active {\n   background: white !important;\n   border-bottom: 3px solid #0073aa !important;\n }\n\n\n .wp_blog_code-tab-content {\n   display: none !important;\n   padding: 20px !important;\n   background: #242B33 !important;\n }\n\n\n .wp_blog_code-tab-content > pre{\n   background: #242B33 !important;\n }\n\n\n .wp_blog_code-tab-content.active {\n   display: block !important;\n }\n\n\n .wp_blog_code-tab-content pre {\n   margin: 0 !important;\n   overflow-x: auto !important;\n }\n\n\n .wp_blog_explanation {\n   max-width: 900px !important;\n   margin: 2rem auto !important;\n   font-family: \"Segoe UI\", sans-serif !important;\n   line-height: 1.6 !important;\n   background: white !important;\ncolor : black !important;\n   padding: 1rem !important;\n   border-radius: 8px !important;\n }\n\n\n .wp_blog_explanation h2 {\n   color: #0073aa !important;\n   font-size: 1.5rem !important;\n   margin-bottom: 0.5rem !important;\n }\n\n\n .wp_blog_explanation code {\n   background: #f1f1f1 !important;\n   padding: 2px 6px !important;\n   border-radius: 4px !important;\n   font-family: monospace !important;\n }\n\n\n.wp_blog_explanation h1,\n.wp_blog_explanation h2,\n.wp_blog_explanation h3,\n.wp_blog_explanation h4,\n.wp_blog_explanation h5,\n.wp_blog_explanation h6,\n.wp_blog_explanation p {\n margin-top: 10px !important;\n margin-bottom: 10px !important;\n}\n<\/style>\n\n<div class=\"wp_blog_explanation\">\n  <h2>Question: Reverse Integer with Overflow Check<\/h2>\n  <p>Write a function <code>reverse(x)<\/code> that takes a 32-bit signed integer and returns its digits reversed. If the reversed value overflows the 32-bit signed integer range, return <code>0<\/code>.<\/p>\n\n  <h2>Requirements<\/h2>\n  <ul>\n    <li>Reverse the digits of a 32-bit signed integer.<\/li>\n    <li>Return <code>0<\/code> if the result overflows.<\/li>\n  <\/ul>\n\n  <h2>Constraints<\/h2>\n  <ul>\n    <li>Time Complexity: <code>O(d)<\/code> where <code>d<\/code> is the number of digits.<\/li>\n    <li>Space Complexity: <code>O(1)<\/code> \u2014 constant space.<\/li>\n  <\/ul>\n\n  <h2>Example<\/h2>\n  <pre><code>Input: 123\nOutput: 321\n\nInput: -123\nOutput: -321\n\nInput: 1534236469\nOutput: 0 (overflow)<\/code><\/pre>\n\n  <h2>Step-by-Step Approach<\/h2>\n  <ul>\n    <li><strong>Preserve the Original:<\/strong> Save <code>x<\/code> in <code>xCopy<\/code>.<\/li>\n    <li><strong>Work with Absolute Value:<\/strong> Use <code>Math.abs(x)<\/code> or <code>abs(x)<\/code> to simplify reversal.<\/li>\n    <li><strong>Reverse Digits:<\/strong>\n      <ul>\n        <li>Initialize <code>rev = 0<\/code>.<\/li>\n        <li>While <code>x != 0<\/code>:\n          <ul>\n            <li><code>last = x % 10<\/code><\/li>\n            <li><code>rev = rev * 10 + last<\/code><\/li>\n            <li><code>x \/\/= 10<\/code><\/li>\n          <\/ul>\n        <\/li>\n      <\/ul>\n    <\/li>\n    <li><strong>Check for Overflow:<\/strong> Return <code>0<\/code> if reversed number is outside 32-bit int range.<\/li>\n    <li><strong>Restore Sign:<\/strong> Return <code>-rev<\/code> if <code>xCopy &lt; 0<\/code>, else <code>rev<\/code>.<\/li>\n  <\/ul>\n<\/div>\n\n<div class=\"wp_blog_code-tabs-container\">\n  <div class=\"wp_blog_code-tabs-header\">\n    <button class=\"wp_blog_code-tab-button active\" data-lang=\"js\">JavaScript<\/button>\n    <button class=\"wp_blog_code-tab-button\" data-lang=\"java\">Java<\/button>\n    <button class=\"wp_blog_code-tab-button\" data-lang=\"cpp\">C++<\/button>\n    <button class=\"wp_blog_code-tab-button\" data-lang=\"c\">C<\/button>\n    <button class=\"wp_blog_code-tab-button\" data-lang=\"py\">Python<\/button>\n  <\/div>\n\n  <div class=\"wp_blog_code-tab-content active\" data-lang=\"js\">\n    <pre><code class=\"language-javascript\">var reverse = function(x) {\n  let xCopy = x;\n  x = Math.abs(x);\n  let rev = 0;\n  while (x > 0) {\n    let last = x % 10;\n    rev = rev * 10 + last;\n    x = Math.floor(x \/ 10);\n  }\n  if (rev > 2**31 - 1) return 0;\n  return xCopy < 0 ? -rev : rev;\n};\n\nconsole.log(reverse(123)); \/\/ 321\n    <\/code><\/pre>\n  <\/div>\n\n  <div class=\"wp_blog_code-tab-content\" data-lang=\"java\">\n    <pre><code class=\"language-java\">public class Solution {\n  public int reverse(int x) {\n    long rev = 0;\n    int n = Math.abs(x);\n    while (n != 0) {\n      int last = n % 10;\n      rev = rev * 10 + last;\n      n \/= 10;\n    }\n    if (rev > Integer.MAX_VALUE) return 0;\n    return x < 0 ? (int)-rev : (int)rev;\n  }\n}\n    <\/code><\/pre>\n  <\/div>\n\n  <div class=\"wp_blog_code-tab-content\" data-lang=\"cpp\">\n    <pre><code class=\"language-cpp\">class Solution {\npublic:\n  int reverse(int x) {\n    long long rev = 0;\n    long long n = x;\n    while (n != 0) {\n      int last = n % 10;\n      rev = rev * 10 + last;\n      n \/= 10;\n    }\n    if (rev > INT_MAX || rev < INT_MIN) return 0;\n    return (int)rev;\n  }\n};\n    <\/code><\/pre>\n  <\/div>\n\n  <div class=\"wp_blog_code-tab-content\" data-lang=\"c\">\n    <pre><code class=\"language-c\">#include &lt;limits.h&gt;\n\nint reverse(int x) {\n  long long rev = 0;\n  long long n = x;\n  while (n != 0) {\n    int last = n % 10;\n    rev = rev * 10 + last;\n    n \/= 10;\n  }\n  if (rev > INT_MAX || rev < INT_MIN) return 0;\n  return (int)rev;\n}\n    <\/code><\/pre>\n  <\/div>\n\n  <div class=\"wp_blog_code-tab-content\" data-lang=\"py\">\n    <pre><code class=\"language-python\">class Solution(object):\n    def reverse(self, x):\n        rev = 0\n        n = abs(x)\n        while n != 0:\n            last = n % 10\n            rev = rev * 10 + last\n            n \/\/= 10\n        if rev > 2**31 - 1:\n            return 0\n        return -rev if x < 0 else rev\n\nsol = Solution()\nprint(sol.reverse(123))  # Output: 321\n    <\/code><\/pre>\n  <\/div>\n<\/div>\n\n<script>\n document.addEventListener('DOMContentLoaded', function () {\n   const buttons = document.querySelectorAll('.wp_blog_code-tab-button');\n   const contents = document.querySelectorAll('.wp_blog_code-tab-content');\n\n   buttons.forEach(button => {\n     button.addEventListener('click', () => {\n       const lang = button.getAttribute('data-lang');\n\n       buttons.forEach(btn => btn.classList.remove('active'));\n       button.classList.add('active');\n\n       contents.forEach(content => {\n         content.classList.toggle('active', content.getAttribute('data-lang') === lang);\n       });\n     });\n   });\n });\n<\/script>\n","protected":false},"excerpt":{"rendered":"<p>Question: Reverse Integer with Overflow Check Write a function reverse(x) that takes a 32-bit signed integer and returns its digits reversed. If the reversed value overflows the 32-bit signed integer range, return 0. Requirements Reverse the digits of a 32-bit signed integer. Return 0 if the result overflows. Constraints Time Complexity: O(d) where d is<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[260,811,810,174,172,173],"tags":[],"class_list":{"0":"post-6245","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-c-c-plus-plus","7":"category-data-structures-and-algorithms","8":"category-dsa","9":"category-java","10":"category-javascript","11":"category-python"},"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/posts\/6245","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/comments?post=6245"}],"version-history":[{"count":2,"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/posts\/6245\/revisions"}],"predecessor-version":[{"id":6250,"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/posts\/6245\/revisions\/6250"}],"wp:attachment":[{"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/media?parent=6245"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/categories?post=6245"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/tags?post=6245"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}