{"id":6812,"date":"2025-06-15T23:25:13","date_gmt":"2025-06-15T17:55:13","guid":{"rendered":"https:\/\/namastedev.com\/blog\/?p=6812"},"modified":"2025-10-22T11:04:57","modified_gmt":"2025-10-22T05:34:57","slug":"find-the-secondlargestnumber","status":"publish","type":"post","link":"https:\/\/namastedev.com\/blog\/find-the-secondlargestnumber\/","title":{"rendered":"Find the Second Largest Number in an Array"},"content":{"rendered":"\n<!-- PrismJS for Syntax Highlighting -->\n<link href=\"https:\/\/cdn.jsdelivr.net\/npm\/prismjs@1.29.0\/themes\/prism-tomorrow.min.css\" rel=\"stylesheet\">\n<script src=\"https:\/\/cdn.jsdelivr.net\/npm\/prismjs@1.29.0\/prism.min.js\"><\/script>\n<script src=\"https:\/\/cdn.jsdelivr.net\/npm\/prismjs@1.29.0\/plugins\/autoloader\/prism-autoloader.min.js\"><\/script>\n\n<style>\n.wp_blog_theme {\n  --primary: #E58C32;\n  --secondary: #030302;\n  --light-bg: #fef9f4;\n  --text-dark: #2d2d2d;\n  --tab-radius: 12px;\n  --shadow: 0 4px 12px rgba(0, 0, 0, 0.08);\n  --code-bg: #001f3f;\n  --code-text: #d4f1ff;\n}\n\n.wp_blog_container {\n  font-family: 'Segoe UI', sans-serif;\n  background: var(--light-bg);\n  margin: 0;\n  padding: 0;\n  color: var(--text-dark);\n}\n\n\/* Heading *\/\n.wp_blog_main-heading {\n  text-align: center;\n  font-size: 2.4rem;\n  color: var(--primary);\n  margin-top: 2.5rem;\n  font-weight: bold;\n}\n\n\/* Explanation Card *\/\n.wp_blog_explanation,\n.wp_blog_code-tabs-container {\n  max-width: 940px;\n  margin: 2rem auto;\n  padding: 2rem;\n  background: white;\n  border-radius: var(--tab-radius);\n  box-shadow: var(--shadow);\n}\n\n\/* Text and Visuals *\/\n.wp_blog_explanation h2 {\n  font-size: 1.4rem;\n  color: var(--primary);\n  margin-bottom: 0.5rem;\n}\n\n.wp_blog_explanation p,\n.wp_blog_explanation li {\n  font-size: 1.05rem;\n  line-height: 1.7;\n  margin: 0.5rem 0;\n}\n\n.wp_blog_explanation code {\n  background: #fef9f4;   \/* light bg instead of dark blue *\/\n  color: #E58C32;        \/* brand orange *\/\n  padding: 3px 6px;\n  border-radius: 4px;\n  font-family: 'Courier New', monospace;\n  font-weight: 600;      \/* optional, makes it pop *\/\n}\n\n.wp_blog_explanation img {\n  max-width: 100%;\n  border-radius: var(--tab-radius);\n  margin-top: 1rem;\n  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);\n}\n\n\/* Tab Buttons *\/\n.wp_blog_code-tabs-header {\n  display: flex;\n  flex-wrap: wrap;\n  gap: 0.5rem;\n  margin-bottom: 1rem;\n}\n\n.wp_blog_code-tab-button {\n  padding: 0.6rem 1.2rem;\n  border: 1px solid var(--primary);\n  background: white;\n  color: var(--primary);\n  border-radius: 50px;\n  font-weight: 600;\n  cursor: pointer;\n  transition: all 0.3s ease;\n}\n\n.wp_blog_code-tab-button:hover {\n  background: var(--secondary);\n}\n\n.wp_blog_code-tab-button.active {\n  background: var(--primary);\n  color: white;\n}\n\n\/* Code Content *\/\n.wp_blog_code-tab-content {\n  display: none;\n  background: var(--code-bg);\n  border-radius: var(--tab-radius);\n}\n\n.wp_blog_code-tab-content.active {\n  display: block;\n}\n\n.wp_blog_code-tab-content pre {\n  margin: 0;\n  padding: 1.5rem;\n  font-size: 1rem;\n  overflow-x: auto;\n  background: var(--code-bg);\n  border-radius: var(--tab-radius);\n  color: var(--code-text);\n}\n\n\/* Dark mode variables *\/\n.wp_blog_theme.dark-mode {\n  --light-bg: #121212;\n  --text-dark: #f5f5f5;\n  --shadow: 0 4px 12px rgba(255, 255, 255, 0.08);\n  --code-bg: #1e1e1e;\n  --code-text: #c5f0ff;\n}\n\n.wp_blog_theme.dark-mode .wp_blog_explanation {\n  background: #1e1e1e;\n}\n\n\/* Dark mode code highlight *\/\n.wp_blog_theme.dark-mode .wp_blog_explanation code {\n  background: #333;\n  color: #ffd27f;\n}\n\n.wp_blog_theme {\n  position: relative; \/* makes it the reference for absolute children *\/\n}\n\n.wp_blog_toggle-btn {\n  position: absolute;\n  top: 1rem;\n  right: 1rem;\n  z-index: 9999;\n  padding: 0.5rem 0.8rem;\n  border-radius: 10%;\n  background: var(--primary);\n  color: white;\n  font-weight: bold;\n  cursor: pointer;\n  border: none;\n  box-shadow: var(--shadow);\n  transition: background 0.3s, transform 0.2s;\n}\n\n.wp_blog_toggle-btn:hover {\n  background: #cc772e;\n}\n\n.wp_blog_theme.dark-mode .wp_blog_code-tabs-container {\n  background: #1e1e1e;\n}\n<\/style>\n\n<div class=\"wp_blog_container wp_blog_theme\">\n    <button id=\"blogNotesThemeToggle\" class=\"wp_blog_toggle-btn\">\ud83c\udf19<\/button>\n\n  <h1 class=\"wp_blog_main-heading\"><\/h1>\n\n  <div class=\"wp_blog_explanation\">\n    <h2>Problem Statement:<\/h2>\n    <p>\n      Write a function <code>secondLargest(arr)<\/code> that returns the second largest <strong>distinct<\/strong> number in an array.\n    <\/p>\n\n    <h2>Requirements:<\/h2>\n    <ul>\n      <li>The array must contain at least two elements.<\/li>\n      <li>If all elements are equal, return: <code>No second largest found<\/code>.<\/li>\n      <li>If the array has fewer than two elements, return: <code>Array should have at least two numbers<\/code>.<\/li>\n    <\/ul>\n\n    <h2>Examples:<\/h2>\n    <p><strong>Input:<\/strong> arr = [0, 3, 5, 2, 7, 9] \u2192 <code>Output: 7<\/code><\/p>\n    <p><strong>Input:<\/strong> arr = [4, 4, 4, 4] \u2192 <code>Output: No second largest found<\/code><\/p>\n    <p><strong>Input:<\/strong> arr = [5] \u2192 <code>Output: Array should have at least two numbers<\/code><\/p>\n    <p><strong>Input:<\/strong> arr = [10, 20] \u2192 <code>Output: 10<\/code><\/p>\n\n    <h2>Constraints:<\/h2>\n    <p><code>Time Complexity: O(n)<\/code> \u2014 Single pass through the array.<\/p>\n    <p><code>Space Complexity: O(1)<\/code> \u2014 Constant space.<\/p>\n\n    <h2>Approach:<\/h2>\n    <ul>\n      <li>Check array length. If fewer than 2 elements, return appropriate message.<\/li>\n      <li>Use two variables: <code>firstLargest<\/code> and <code>secondLargest<\/code>.<\/li>\n      <li>Ignore duplicates by checking <code>num !== firstLargest<\/code> before assigning <code>secondLargest<\/code>.<\/li>\n    <\/ul>\n\n    <h2>Visualisation:<\/h2>\n    <img decoding=\"async\" src=\"https:\/\/namastedev.com\/blog\/wp-content\/uploads\/2025\/06\/Screenshot-2025-06-21-at-1.06.59\u202fAM.png\" alt=\"Second Largest Visual\">\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=\"py\">Python<\/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=\"cs\">C#<\/button>\n    <\/div>\n\n    <!-- JavaScript -->\n    <div class=\"wp_blog_code-tab-content active\" data-lang=\"js\">\n      <pre><code class=\"language-javascript\">\nfunction secondLargest(arr) {\n  if (arr.length < 2) return \"Array should have at least two numbers\";\n  let first = -Infinity, second = -Infinity;\n  for (let num of arr) {\n    if (num > first) {\n      second = first;\n      first = num;\n    } else if (num > second && num !== first) {\n      second = num;\n    }\n  }\n  return second === -Infinity ? \"No second largest found\" : second;\n}\nconsole.log(secondLargest([0, 3, 5, 2, 7, 9])); \/\/ 7\n<\/code><\/pre>\n    <\/div>\n\n    <!-- Python -->\n    <div class=\"wp_blog_code-tab-content\" data-lang=\"py\">\n      <pre><code class=\"language-python\">\ndef second_largest(arr):\n    if len(arr) < 2:\n        return \"Array should have at least two numbers\"\n    first = float('-inf')\n    second = float('-inf')\n    for num in arr:\n        if num > first:\n            second = first\n            first = num\n        elif num > second and num != first:\n            second = num\n    return second if second != float('-inf') else \"No second largest found\"\n\nprint(second_largest([0, 3, 5, 2, 7, 9]))  # 7\n<\/code><\/pre>\n    <\/div>\n\n    <!-- Java -->\n    <div class=\"wp_blog_code-tab-content\" data-lang=\"java\">\n      <pre><code class=\"language-java\">\npublic class Main {\n  public static String secondLargest(int[] arr) {\n    if (arr.length < 2) return \"Array should have at least two numbers\";\n    int first = Integer.MIN_VALUE, second = Integer.MIN_VALUE;\n    for (int num : arr) {\n      if (num > first) {\n        second = first;\n        first = num;\n      } else if (num > second && num != first) {\n        second = num;\n      }\n    }\n    return (second == Integer.MIN_VALUE) ? \"No second largest found\" : String.valueOf(second);\n  }\n\n  public static void main(String[] args) {\n    int[] arr = {0, 3, 5, 2, 7, 9};\n    System.out.println(secondLargest(arr));\n  }\n}\n<\/code><\/pre>\n    <\/div>\n\n    <!-- C++ -->\n    <div class=\"wp_blog_code-tab-content\" data-lang=\"cpp\">\n      <pre><code class=\"language-cpp\">\n#include &lt;iostream&gt;\n#include &lt;climits&gt;\nusing namespace std;\n\nstring secondLargest(int arr[], int n) {\n  if (n < 2) return \"Array should have at least two numbers\";\n  int first = INT_MIN, second = INT_MIN;\n  for (int i = 0; i < n; i++) {\n    if (arr[i] > first) {\n      second = first;\n      first = arr[i];\n    } else if (arr[i] > second && arr[i] != first) {\n      second = arr[i];\n    }\n  }\n  return (second == INT_MIN) ? \"No second largest found\" : to_string(second);\n}\n\nint main() {\n  int arr[] = {0, 3, 5, 2, 7, 9};\n  cout &lt;&lt; secondLargest(arr, 6) &lt;&lt; endl;\n  return 0;\n}\n<\/code><\/pre>\n    <\/div>\n\n    <!-- C -->\n    <div class=\"wp_blog_code-tab-content\" data-lang=\"c\">\n      <pre><code class=\"language-c\">\n#include &lt;stdio.h&gt;\n#include &lt;limits.h&gt;\n\nconst char* secondLargest(int arr[], int n, int* second) {\n  if (n < 2) return \"Array should have at least two numbers\";\n  int first = INT_MIN;\n  *second = INT_MIN;\n  for (int i = 0; i < n; i++) {\n    if (arr[i] > first) {\n      *second = first;\n      first = arr[i];\n    } else if (arr[i] > *second && arr[i] != first) {\n      *second = arr[i];\n    }\n  }\n  return (*second == INT_MIN) ? \"No second largest found\" : NULL;\n}\n\nint main() {\n  int arr[] = {0, 3, 5, 2, 7, 9};\n  int second;\n  const char* msg = secondLargest(arr, 6, &second);\n  if (msg) printf(\"%s\\\\n\", msg);\n  else printf(\\\"%d\\\\n\\\", second);\n  return 0;\n}\n<\/code><\/pre>\n    <\/div>\n\n    <!-- C# -->\n    <div class=\"wp_blog_code-tab-content\" data-lang=\"cs\">\n      <pre><code class=\"language-csharp\">\nusing System;\n\nclass Program {\n  static string SecondLargest(int[] arr, out int second) {\n    second = int.MinValue;\n    if (arr.Length < 2) return \"Array should have at least two numbers\";\n    int first = int.MinValue;\n    foreach (int num in arr) {\n      if (num > first) {\n        second = first;\n        first = num;\n      } else if (num > second && num != first) {\n        second = num;\n      }\n    }\n    return (second == int.MinValue) ? \"No second largest found\" : null;\n  }\n\n  static void Main() {\n    int[] arr = { 0, 3, 5, 2, 7, 9 };\n    int second;\n    string msg = SecondLargest(arr, out second);\n    if (msg != null)\n      Console.WriteLine(msg);\n    else\n      Console.WriteLine(\"Second largest: \" + second);\n  }\n}\n<\/code><\/pre>\n    <\/div>\n  <\/div>\n<\/div>\n\n<script>\ndocument.addEventListener(\"DOMContentLoaded\", () => {\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      contents.forEach((content) => content.classList.remove(\"active\"));\n\n      button.classList.add(\"active\");\n      document\n        .querySelector(`.wp_blog_code-tab-content[data-lang=\"${lang}\"]`)\n        .classList.add(\"active\");\n    });\n  });\n\n  const themeToggle = document.getElementById(\"blogNotesThemeToggle\");\n  const themeContainer = document.querySelector(\".wp_blog_theme\");\n\n  themeToggle.addEventListener(\"click\", () => {\n    themeContainer.classList.toggle(\"dark-mode\");\n    themeToggle.textContent =\n      themeContainer.classList.contains(\"dark-mode\") ? \"\u2600\ufe0f\" : \"\ud83c\udf19\";\n  });\n});\n<\/script>\n\n","protected":false},"excerpt":{"rendered":"<p>\ud83c\udf19 Problem Statement: Write a function secondLargest(arr) that returns the second largest distinct number in an array. Requirements: The array must contain at least two elements. If all elements are equal, return: No second largest found. If the array has fewer than two elements, return: Array should have at least two numbers. Examples: Input: arr<\/p>\n","protected":false},"author":108,"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":[322,260,176,175,810,222,174,172,173],"tags":[],"class_list":{"0":"post-6812","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-algorithms-and-data-structures","7":"category-c-c-plus-plus","8":"category-csharp","9":"category-cplusplus","10":"category-dsa","11":"category-interview","12":"category-java","13":"category-javascript","14":"category-python"},"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/posts\/6812","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\/108"}],"replies":[{"embeddable":true,"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/comments?post=6812"}],"version-history":[{"count":6,"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/posts\/6812\/revisions"}],"predecessor-version":[{"id":10524,"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/posts\/6812\/revisions\/10524"}],"wp:attachment":[{"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/media?parent=6812"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/categories?post=6812"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/tags?post=6812"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}