Analytics: Longest Unique Session Window
Also known as: Longest Substring Without Repeating Characters
YouTube Analytics: User Engagement Tracking You're analyzing YouTube viewing patterns. Each character represents a video category watched. Find the longest streak where a user watched different categories without repeating (indicates exploration behavior). Example: "abcabcbb" → 3 ("abc" is longest unique streak)
I jump the left edge straight past the duplicate instead of stepping it. One pass, and the window never revisits a character.
Meet Coco
Coco is an AI study partner, not a person. She listens while you explain your code, asks what a line does and never hands you the fix. Typing with Coco is free when you sign in, up to a daily limit. Talking with her out loud comes with the $79 pack. Anyone can open the editor and run their code.
Each locked part opens in the editor once the part before it passes.