{"id":"counter-then-deduplicate-idiom","text":"Frequency-based problems follow a two-step pattern: build a frequency map with `Counter`, then apply a predicate (uniqueness, equality, sorting) over the counts.","truth_value":"IN","source":"entries/2026/06/06/unique-number-of-occurrences-solution.md","source_url":"","source_hash":"","justifications":[],"dependents":["counter-two-pass-frequency-pipeline"],"metadata":{},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"counter-then-deduplicate-idiom","truth_value":"IN","reason":"premise"}]}}