{"id":"climbing-stairs-constant-space","text":"The climbing-stairs solution uses two rolling variables (`a`, `b`) with tuple swap instead of an O(n) DP array, achieving O(1) auxiliary space.","truth_value":"IN","source":"entries/2026/06/06/climbing-stairs-solution.md","source_url":"","source_hash":"","justifications":[],"dependents":[],"metadata":{},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"climbing-stairs-constant-space","truth_value":"IN","reason":"premise"}]}}