Longest Substring Without Repeating Characters — LeetCode #3 (Medium)
The article discusses the problem of finding the length of the longest substring without repeating characters. It explains the sliding window technique used to solve this problem efficiently. The author provides a Python code implementation and a detailed walkthrough of the algorithm.
- ▪The problem requires returning the length of the longest substring that contains no duplicate characters.
- ▪The sliding window technique involves using two pointers to manage the current substring and a set to track characters.
- ▪The provided Python code initializes a set and uses a loop to iterate through the string while adjusting the pointers as needed.
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Story provenance
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Record
| Original publisher | DEV.to (Top) |
| Canonical URL | https://dev.to/logixydev/longest-substring-without-repeating-characters-leetcode-3-medium-3l61 |
| Publication time | Mon, 18 May 2026 19:32:33 +0000 |
| Retrieval time | 2026-05-18T19:34:56.983Z |
| Last seen | 2026-05-18T19:34:56.983Z |
| Headline source | Publisher (no WeSearch rewrite) |
| Excerpt source | publisher body |
| Excerpt method | First ~120 words (~800 chars) of extracted publisher body, fair-use limited. |
| Summary | WeSearch · cerebras-chat (WeSearch summarizer) |
| Summary source text | contentText |
| Citation coverage | Summary is a WeSearch-generated derivative; primary citation is the original publisher URL. |
| Cluster | QAfXwBByCF03 |
| Cluster logic | Grouped by semantic title/content similarity across sources within a rolling window. Same-publisher template collisions are excluded from coverage comparison. |
| Ranking reason | Story pages are not engagement-ranked. Hub feeds use recency, with optional source-diversified chronological ordering (cap consecutive stories per source). No personalized ranking. |
| Publisher visit | Yes — open original |
| Substitutes article? | No — link-out required for full text |
Rights status (four layers)
WeSearch handling by dimension
| Indexing | May the item be indexed (stored, ranked, made findable)? | Allowed |
| Snippet | May a short excerpt of the publisher's text be shown? | Allowed |
| AI summary | May WeSearch generate its own short summary of the article? | Limited |
| Retrieval / RAG | May the content be exposed for third-party retrieval-augmented generation? | Not asserted |
| Model training | May the content be used to train AI models? | Not asserted |
| Commercial reuse | May the content be reused commercially? | Not permitted |
Basis: Derived from the published RSS/Atom feed. Contact: [email protected]. Reviewed: 2026-07-24.
Opening excerpt (first ~120 words) tap to expand
try { if(localStorage) { let currentUser = localStorage.getItem('current_user'); if (currentUser) { currentUser = JSON.parse(currentUser); if (currentUser.id === 245317) { document.getElementById('article-show-container').classList.add('current-user-is-article-author'); } } } } catch (e) { console.error(e); } Shubham Gupta for Logixy Posted on May 18 • Originally published at youtu.be Longest Substring Without Repeating Characters — LeetCode #3 (Medium) #leetcode #python #algorithms #hashtable The Problem Given a string s, return the length of the longest substring that contains no duplicate characters. Example Input: s = "abcabcbb" Output: 3 The answer is "abc", with the length of 3. Note that "bca" and "cab" are also correct answers.
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Excerpt limited to ~120 words for fair-use compliance. The full article is at DEV.to (Top).
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