{"id":6060,"date":"2025-05-27T17:54:39","date_gmt":"2025-05-27T12:24:39","guid":{"rendered":"https:\/\/namastedev.com\/blog\/?p=6060"},"modified":"2025-07-22T21:58:21","modified_gmt":"2025-07-22T16:28:21","slug":"testing-purpose","status":"publish","type":"post","link":"https:\/\/namastedev.com\/blog\/testing-purpose\/","title":{"rendered":"Time Complexity Notes"},"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<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  .wp_blog_code-tabs-header {\n    background: #f7f7f7 !important;\n    display: flex !important;\n    border-bottom: 1px solid #ddd !important;\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  .wp_blog_code-tab-button.active {\n    background: white !important;\n    border-bottom: 3px solid #0073aa !important;\n  }\n\n  .wp_blog_code-tab-content {\n    display: none !important;\n    padding: 20px !important;\n    background: #242B33 !important;\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  .wp_blog_code-tab-content pre {\n    margin: 0 !important;\n    overflow-x: auto !important;\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  .wp_blog_explanation h2 {\n    color: #0073aa !important;\n    font-size: 1.5rem !important;\n    margin-bottom: 0.5rem !important;\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.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>Approach (Brute Force &#8211; Hash Map)<\/h2>\n  <p>Create an empty hash map to store counts of each element.<\/p>\n  <ul>\n    <li>Loop through the array, update the count for each element.<\/li>\n    <li>Loop through the array again to find the element with count 1.<\/li>\n    <li>Return that element.<\/li>\n  <\/ul>\n\n  <h2>Dry Run<\/h2>\n  <p><strong>Input:<\/strong> [4, 1, 2, 1, 2]<\/p>\n  <p><strong>Step 1: Counting frequency<\/strong><\/p>\n  <pre><code>hash = {}\n\nInsert 4 \u2192 hash[4] = 1\nInsert 1 \u2192 hash[1] = 1\nInsert 2 \u2192 hash[2] = 1\nUpdate 1 \u2192 hash[1] = 2\nUpdate 2 \u2192 hash[2] = 2<\/code><\/pre>\n  <p><strong>Step 2: Find the element with count 1<\/strong><\/p>\n  <pre><code>4 \u2192 hash[4] = 1 \u2192 return 4<\/code><\/pre>\n  <p><strong>Output:<\/strong> 4<\/p>\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=\"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=\"java\">Java<\/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\">\nvar singleNumber = function(nums) {\n    let hash = {};\n    for(let i = 0; i < nums.length; i++) {\n        if (!hash[nums[i]]) {\n            hash[nums[i]] = 1;\n        } else {\n            hash[nums[i]]++;\n        }\n    }\n\n    for(let i = 0; i < nums.length; i++) {\n        if (hash[nums[i]] === 1) {\n            return nums[i];\n        }\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\">\n#include &lt;vector&gt;\n#include &lt;unordered_map&gt;\nusing namespace std;\n\nclass Solution {\npublic:\n    int singleNumber(vector&lt;int&gt;& nums) {\n        unordered_map&lt;int, int&gt; hash;\n        for (int num : nums) {\n            hash[num]++;\n        }\n        for (int num : nums) {\n            if (hash[num] == 1)\n                return num;\n        }\n        return -1;\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\">\n#include &lt;stdio.h&gt;\n\nint singleNumber(int* nums, int numsSize){\n    for (int i = 0; i < numsSize; i++) {\n        int count = 0;\n        for (int j = 0; j < numsSize; j++) {\n            if (nums[j] == nums[i]) count++;\n        }\n        if (count == 1) return nums[i];\n    }\n    return -1;\n}\n    <\/code><\/pre>\n  <\/div>\n\n  <div class=\"wp_blog_code-tab-content\" data-lang=\"java\">\n    <pre><code class=\"language-java\">\nimport java.util.HashMap;\n\npublic class Solution {\n    public int singleNumber(int[] nums) {\n        HashMap&lt;Integer, Integer&gt; hash = new HashMap&lt;&gt;();\n        for (int num : nums) {\n            hash.put(num, hash.getOrDefault(num, 0) + 1);\n        }\n        for (int num : nums) {\n            if (hash.get(num) == 1) {\n                return num;\n            }\n        }\n        return -1;\n    }\n}\n    <\/code><\/pre>\n  <\/div>\n\n  <div class=\"wp_blog_code-tab-content\" data-lang=\"py\">\n    <pre><code class=\"language-python\">\nclass Solution:\n    def singleNumber(self, nums):\n        hash = {}\n        for num in nums:\n            hash[num] = hash.get(num, 0) + 1\n        \n        for num in nums:\n            if hash[num] == 1:\n                return num\n    <\/code><\/pre>\n  <\/div>\n<\/div>\n<a href=\"https:\/\/leetcode.com\/problems\/two-sum\/description\/\" target=\"blank\">Solve this problem.<\/a>\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\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Approach (Brute Force &#8211; Hash Map) Create an empty hash map to store counts of each element. Loop through the array, update the count for each element. Loop through the array again to find the element with count 1. Return that element. Dry Run Input: [4, 1, 2, 1, 2] Step 1: Counting frequency hash<\/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":[322,176,175,174,172,173],"tags":[],"class_list":["post-6060","post","type-post","status-publish","format-standard","category-algorithms-and-data-structures","category-csharp","category-cplusplus","category-java","category-javascript","category-python"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/posts\/6060","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=6060"}],"version-history":[{"count":19,"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/posts\/6060\/revisions"}],"predecessor-version":[{"id":6106,"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/posts\/6060\/revisions\/6106"}],"wp:attachment":[{"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/media?parent=6060"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/categories?post=6060"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/tags?post=6060"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}