LC 3
Longest Substring Without Repeating Characters
Medium · LC 1–100
Candidate solution routes
Primary
FreeVariable-Size Sliding Window
Invariant: left and right never retreat; whenever a result is recorded, the maintained state exactly matches [left,right] and satisfies the variant's validity or minimality condition.
candidate confidence: 0.740 · metadata_only
How to use this page
Read the statement and constraints first, then validate recognition signals, invariant, and complexity. Candidate score is not correctness evidence.