{"id":7940,"date":"2022-09-17T23:15:00","date_gmt":"2022-09-17T17:45:00","guid":{"rendered":"https:\/\/www.codingbroz.com\/?p=7940"},"modified":"2022-09-17T11:06:36","modified_gmt":"2022-09-17T05:36:36","slug":"longest-substring-without-repeating-characters-leetcode-solution","status":"publish","type":"post","link":"https:\/\/www.codingbroz.com\/longest-substring-without-repeating-characters-leetcode-solution\/","title":{"rendered":"Longest Substring Without Repeating Characters &#8211; Leetcode Solution"},"content":{"rendered":"\n<p>In this post, we are going to solve the<strong> 3. Longest Substring Without Repeating Characters<\/strong> problem of Leetcode. This problem <strong><strong><strong>3. Longest Substring Without Repeating Characters<\/strong><\/strong><\/strong> is a Leetcode <strong>medium <\/strong>level problem. Let&#8217;s see code, <strong><strong>3. Longest Substring Without Repeating Characters<\/strong><\/strong>.<\/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-663628d1eb5cc\" 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-663628d1eb5cc\" checked \/><nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><ul class='ez-toc-list-level-2' ><li class='ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.codingbroz.com\/longest-substring-without-repeating-characters-leetcode-solution\/#Problem\" title=\"Problem\">Problem<\/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\/longest-substring-without-repeating-characters-leetcode-solution\/#Example_1\" title=\"Example 1 :\">Example 1 :<\/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\/longest-substring-without-repeating-characters-leetcode-solution\/#Example_2\" title=\"Example 2 :\">Example 2 :<\/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\/longest-substring-without-repeating-characters-leetcode-solution\/#Example_3\" title=\"Example 3 :\">Example 3 :<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.codingbroz.com\/longest-substring-without-repeating-characters-leetcode-solution\/#Constraints\" title=\"Constraints\">Constraints<\/a><\/li><\/ul><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.codingbroz.com\/longest-substring-without-repeating-characters-leetcode-solution\/#Longest_Substring_Without_Repeating_Characters_%E2%80%93_Leetcode_Solution\" title=\"Longest Substring Without Repeating Characters &#8211; Leetcode Solution\">Longest Substring Without Repeating Characters &#8211; Leetcode Solution<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.codingbroz.com\/longest-substring-without-repeating-characters-leetcode-solution\/#3_Longest_Substring_Without_Repeating_Characters_%E2%80%93_Solution_in_Java\" title=\"3. Longest Substring Without Repeating Characters &#8211; Solution in Java\">3. Longest Substring Without Repeating Characters &#8211; Solution in Java<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.codingbroz.com\/longest-substring-without-repeating-characters-leetcode-solution\/#3_Longest_Substring_Without_Repeating_Characters_%E2%80%93_Solution_in_C\" title=\"3. Longest Substring Without Repeating Characters &#8211; Solution in C++\">3. Longest Substring Without Repeating Characters &#8211; Solution in C++<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.codingbroz.com\/longest-substring-without-repeating-characters-leetcode-solution\/#3_Longest_Substring_Without_Repeating_Characters_%E2%80%93_Solution_in_Python\" title=\"3. Longest Substring Without Repeating Characters &#8211; Solution in Python\">3. Longest Substring Without Repeating Characters &#8211; Solution in Python<\/a><\/li><\/ul><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Problem\"><\/span><strong>Problem<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Given a string <code>s<\/code>, find the length of the <strong>longest substring<\/strong> without repeating characters.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Example_1\"><\/span><strong>Example 1 :<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<pre class=\"wp-block-code has-ast-global-color-5-color has-ast-global-color-8-background-color has-text-color has-background\"><code>\nInput: s = \"abcabcbb\"\r\nOutput: 3\r\nExplanation: The answer is \"abc\", with the length of 3.\n<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Example_2\"><\/span><strong>Example 2 :<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<pre class=\"wp-block-code has-ast-global-color-5-color has-ast-global-color-8-background-color has-text-color has-background\"><code>\nInput: s = \"bbbbb\"\r\nOutput: 1\r\nExplanation: The answer is \"b\", with the length of 1.\n<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Example_3\"><\/span><strong>Example 3 :<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<pre class=\"wp-block-code has-ast-global-color-5-color has-ast-global-color-8-background-color has-text-color has-background\"><code>\nInput: s = \"pwwkew\"\r\nOutput: 3\r\nExplanation: The answer is \"wke\", with the length of 3.\r\nNotice that the answer must be a substring, \"pwke\" is a subsequence and not a substring.\n<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Constraints\"><\/span><strong>Constraints<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul><li><code>0 &lt;= s.length &lt;= 5 * 10<sup>4<\/sup><\/code><\/li><li><code>s<\/code> consists of English letters, digits, symbols and spaces.<\/li><\/ul>\n\n\n\n<p>Now, let&#8217;s see the code of <strong><strong><strong><strong>3. Longest Substring Without Repeating Characters<\/strong><\/strong><\/strong><\/strong> &#8211; Leetcode Solution.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Longest_Substring_Without_Repeating_Characters_%E2%80%93_Leetcode_Solution\"><\/span><strong><strong><strong><strong>Longest Substring Without Repeating Characters<\/strong><\/strong><\/strong><\/strong> &#8211; Leetcode Solution<span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"3_Longest_Substring_Without_Repeating_Characters_%E2%80%93_Solution_in_Java\"><\/span><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong>3. Longest Substring Without Repeating Characters<\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong> &#8211; Solution in 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=\"\">class Solution {\n    public int lengthOfLongestSubstring(String s) {\n        int n = s.length(), longest = 0;\n        int[] nextIndex = new int[128]; \n\n        for (int r=0, l=0; r&lt;n; r++) {\n            l = Math.max(nextIndex[s.charAt(r)], l); \n            longest = Math.max(longest, r - l + 1);\n            nextIndex[s.charAt(r)] = r + 1;\n        }\n\n        return longest;\n    }\n}<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"3_Longest_Substring_Without_Repeating_Characters_%E2%80%93_Solution_in_C\"><\/span><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong><strong>3. Longest Substring Without Repeating Characters<\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong> &#8211; Solution in <\/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=\"\">class Solution {\npublic:\n    int lengthOfLongestSubstring(string s) {\n        int n = s.length(), longest = 0;\n        vector&lt;int> nextIndex(128); \n\n        for (int r=0, l=0; r&lt;n; r++) {\n            l = max(nextIndex[s[r]], l); \n            longest = max(longest, r - l + 1);\n            nextIndex[s[r]] = r + 1;\n        }\n\n        return longest;\n    }\n};<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"3_Longest_Substring_Without_Repeating_Characters_%E2%80%93_Solution_in_Python\"><\/span><strong><strong><strong><strong><strong><strong><strong><strong>3. Longest Substring Without Repeating Characters<\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong> <strong><strong><strong>&#8211; Solution in <\/strong><\/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=\"\">class Solution:\n    def lengthOfLongestSubstring(self, s):\n        start = maxLength = 0\n        usedChar = {}\n        \n        for i in range(len(s)):\n            if s[i] in usedChar and start &lt;= usedChar[s[i]]:\n                start = usedChar[s[i]] + 1\n            else:\n                maxLength = max(maxLength, i - start + 1)\n\n            usedChar[s[i]] = i\n\n        return maxLength<\/pre>\n\n\n\n<p><strong>Note:<\/strong> This problem <strong><strong><strong><strong><a href=\"https:\/\/leetcode.com\/problems\/longest-substring-without-repeating-characters\/\" target=\"_blank\" rel=\"noreferrer noopener\">3. Longest Substring Without Repeating Characters<\/a><\/strong><\/strong><\/strong><\/strong> is generated by <strong><a href=\"https:\/\/leetcode.com\/\" target=\"_blank\" rel=\"noreferrer noopener\">Leetcode<\/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 are going to solve the 3. Longest Substring Without Repeating Characters problem of Leetcode. This problem 3. Longest Substring Without Repeating Characters is a Leetcode medium level problem. Let&#8217;s see code, 3. Longest Substring Without Repeating Characters.<\/p>\n","protected":false},"author":3,"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":[688],"tags":[130,689,789],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/posts\/7940"}],"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\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/comments?post=7940"}],"version-history":[{"count":3,"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/posts\/7940\/revisions"}],"predecessor-version":[{"id":8033,"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/posts\/7940\/revisions\/8033"}],"wp:attachment":[{"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/media?parent=7940"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/categories?post=7940"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/tags?post=7940"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}