{"results":[{"id":"add-strings-avoids-int-conversion","text":"`addStrings` converts between characters and digit values using `ord()/chr()` arithmetic (`ord(c) - 48`, `chr(d + 48)`) and never calls `int()` or `str()`, satisfying the problem's constraint against built-in integer conversion.","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null,"source_type":""},{"id":"add-to-array-form-prepend-quadratic-worst-case","text":"When `k` has more digits than `num`, each extra digit triggers an O(n) `list.insert(0, ...)`, making the overflow phase O(d*n) rather than the O(max(n,d)) achievable with append-and-reverse.","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null,"source_type":""},{"id":"base7-digits-lsb-first","text":"Digits in convert_to_base7 are accumulated least-significant-first via repeated `% 7` and `//= 7`, then reversed at the end — the standard accumulate-then-reverse idiom that avoids O(n) prepend costs.","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null,"source_type":""},{"id":"base7-sign-magnitude","text":"Negative inputs in convert_to_base7 are handled by converting to absolute value and prepending `\"-\"`, avoiding Python's floor-division behavior on negative numbers which would complicate digit extraction.","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null,"source_type":""},{"id":"cell-range-single-char-columns","text":"`cell_range` parses the input string by fixed character positions (s[0], s[1], s[3], s[4]), so it only handles single-letter columns (A-Z) and single-digit rows (1-9).","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null,"source_type":""},{"id":"clock-times-enumerate-over-case-logic","text":"`count_valid_times` iterates over all 24 hours and 60 minutes (84 total iterations) and pattern-matches, rather than building conditional case tables per digit position.","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null,"source_type":""},{"id":"common-digit-always-optimal","text":"When both digit arrays share a digit, the smallest shared digit is always the answer, because any single-digit value (1-9) is strictly less than any two-digit value (11-99).","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null,"source_type":""},{"id":"confusing-number-rotate-dict-dual-purpose","text":"The `rotate` dict serves as both a validity whitelist (membership test for rotatable digits) and a transformation function (mapping each digit to its rotation), avoiding separate validation and transformation steps.","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null,"source_type":""},{"id":"confusing-number-single-pass","text":"The solution extracts digits right-to-left and rebuilds the rotated number left-to-right in one pass, simultaneously reversing digit order and applying the rotation mapping in O(d) time.","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null,"source_type":""},{"id":"confusing-number-valid-digits","text":"Only digits 0, 1, 6, 8, 9 survive 180-degree rotation; any other digit in the input causes an immediate `False` return via the `rotate` dict membership check.","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null,"source_type":""},{"id":"counter-default-zero","text":"`Counter[str(i)]` returns 0 for digits not present in `num`, which is load-bearing for correctness when the expected count is also 0 — a plain `dict` would raise `KeyError`","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null,"source_type":""},{"id":"counter-max-keys-bounded-by-digit-sum","text":"The Counter produced by `countBalls` has at most 45 entries (max digit sum for a 5-digit number in [1, 100000]), making space O(1) regardless of input range size.","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null,"source_type":""},{"id":"digit-accumulation-is-greedy","text":"Consecutive digits in `abbr` are always parsed as a single number via a greedy inner `while` loop (e.g., `\"12\"` means skip 12, not skip 1 then skip 2).","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null,"source_type":""},{"id":"digit-count-alias-is-bound-method","text":"`rearrange_array` is a bound method on a throwaway `Solution()` instance, not a standalone function; this is the repo convention for exposing a uniform entry point to tests","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null,"source_type":""},{"id":"digit-count-misnamed-alias","text":"The alias `rearrange_array` has no semantic relationship to the digit-count problem; it's likely a copy-paste artifact from the project's code generation pipeline","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null,"source_type":""},{"id":"digit-extraction-modular-idiom","text":"The `n % 10` / `n //= 10` loop for digit extraction is a recurring idiom across dozens of solutions in this repo (e.g., `self-dividing-numbers`, `alternating-digit-sum`, `add-digits`, `subtract-the-product-and-sum-of-digits-of-an-integer`)","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null,"source_type":""},{"id":"digit-extraction-prefers-mod-arithmetic","text":"Multiple solutions (`sum-of-digits-in-base-k`, `sum-of-digits-in-the-minimum-number`) extract digits via `% 10` / `// 10` loops rather than string conversion, avoiding allocation.","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null,"source_type":""},{"id":"digit-extraction-uses-modular-arithmetic","text":"Digit extraction across the repo uses `% 10` / `//= 10` modular arithmetic exclusively, avoiding `str()` conversion and intermediate string allocations.","truth_value":"IN","justification_count":0,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null,"source_type":""},{"id":"digit-operations-handle-all-nonneg-inputs","text":"String-based digit manipulation solutions correctly handle all non-negative integer inputs including zero and multi-digit numbers.","truth_value":"OUT","justification_count":1,"dependent_count":0,"challenges":[],"last_reviewed":null,"review_result":null,"source_type":""},{"id":"digit-remapping-greedy-targets-positional-extremes","text":"Digit remapping achieves both its minimum and maximum through a single greedy digit substitution targeting the most positionally impactful digit — the leading digit maps to 0 for minimum (maximum positional weight), the leftmost non-9 digit maps to 9 for maximum (highest available gain) — sharing the same structural principle (leftmost-significant substitution) despite targeting opposite extremes.","truth_value":"IN","justification_count":1,"dependent_count":0,"challenges":[],"last_reviewed":"2026-06-07T22:02:22","review_result":"pass","source_type":"derived"}],"count":109,"limit":20,"offset":0}