{
  "title": "Longest Substring Without Repeating Characters",
  "category": "Sliding Window",
  "slug": "longest-substring-without-repeating-characters",
  "officialUrl": "https://leetcode.com/problems/longest-substring-without-repeating-characters/",
  "difficulty": "Medium",
  "tags": ["sliding window", "string", "last seen index"],
  "status": "solved",
  "order": 1,
  "summary": "Track the longest contiguous substring whose characters stay unique."
}