highest-cost-scenario-identification

# Highest Cost Scenario Identification This skill covers two question types in the dabstep dataset, both requiring fee calculation from `fees.json`. ## Fee Formula From `manual.md`: ``` fee = fixed_amount + rate * transaction_value / 10000 ``` Null fields in a fee rule apply to all possible values of that field. An empty list `[]` means the rule does NOT apply to any value of that dimension. ## Data Files - `fees.json`: 1000 fee rules with fields: `card_scheme`, `account_type`, `capture_delay`, `monthly_fraud_level`, `monthly_volume`, `merchant_category_code`, `is_credit`, `aci`, `fixed_amount`, `rate`, `intracountry` - `manual.md`: domain definitions (ACI values A–F, account types, fee formula) - `merchant_category_codes.csv`: MCC descriptions only — do NOT use as a filter --- ## Question Type 1: Most Expensive MCC **Pattern**: "What is the most expensive MCC for a transaction of X euros, in general?" **Algorithm**: 1. Load `fees.json` 2. For every rule, compute `fee = fixed_amount + rate * X / 10000` 3. For each MCC in the rule's `merchant_category_code` list, track the maximum fee seen 4. Find the global maximum fee across all MCCs 5. Return all MCCs (sorted ascending) that achieve this maximum fee **Critical**: Include ALL MCCs from `fees.json` fee rules. Do NOT filter to only MCCs present in `merchant_category_codes.csv` — some valid MCCs in the fee rules (e.g., 3003, 7231) are absent from that CSV but are correct answers. **Output format**: Comma-separated list of MCC integers, sorted ascending. **Example code**: ```python import json with open('fees.json') as f: fees = json.load(f) transaction_value = X # from question mcc_max_fees = {} for rule in fees: mcc_list = rule['merchant_category_code'] if not mcc_list: # skip empty lists continue fee = rule['fixed_amount'] + rule['rate'] * transaction_value / 10000 for mcc in mcc_list: if mcc not in mcc_max_fees or fee > mcc_max_fees[mcc]: mcc_max_fees[mcc] = fee max_fee = max(mcc_max_fees.values()) result = sorted([mcc for mcc, f in mcc_max_fees.items() if f == max_fee]) print(', '.join(str(m) for m in result)) ``` --- ## Question Type 2: Most Expensive ACI **Pattern**: "For a credit transaction of X euros on [CardScheme], what would be the most expensive ACI? In the case of a draw between multiple ACIs, return the ACI with the lowest alphabetical order." **Algorithm**: 1. Load `fees.json` 2. Filter rules: `card_scheme == CardScheme` AND (`is_credit == True` OR `is_credit == None`) 3. For each filtered rule, skip if `aci` list is empty (`[]`) 4. Compute `fee = fixed_amount + rate * X / 10000` 5. For each ACI in the rule's `aci` list, track the maximum fee seen 6. Find the global maximum fee across all ACIs 7. Return the ACI(s) achieving this maximum; if tied, return the alphabetically lowest **Output format**: A list with one letter, e.g., `['C']`. The answer is the ACI letter, NOT the fee amount. **Card schemes in dataset**: `GlobalCard`, `NexPay`, `TransactPlus`, `SwiftCharge` **ACI values**: A, B, C, D, E, F (G appears in the manual but not in any fee rule in this dataset) **Example code**: ```python import json with open('fees.json') as f: fees = json.load(f) card_scheme = 'GlobalCard' # from question transaction_value = 1 # from question aci_max_fees = {} for rule in fees: if rule['card_scheme'] != card_scheme: continue # is_credit: True = credit only, False = debit only, None = both if rule['is_credit'] is not None and rule['is_credit'] != True: continue aci_list = rule['aci'] if not aci_list: # skip empty aci lists continue fee = rule['fixed_amount'] + rule['rate'] * transaction_value / 10000 for aci in aci_list: if aci not in aci_max_fees or fee > aci_max_fees[aci]: aci_max_fees[aci] = fee max_fee = max(aci_max_fees.values()) winners = sorted([aci for aci, f in aci_max_fees.items() if f == max_fee]) answer = winners[0] # lowest alphabetical in case of tie print([answer]) ``` --- ## Common Mistakes to Avoid 1. **MCC filtering**: Never exclude an MCC just because it's absent from `merchant_category_codes.csv`. The fee rules are the authoritative source. 2. **ACI answer format**: The answer must be the ACI letter (e.g., `C`), NOT the computed fee amount (e.g., `0.23`). The `0.23` example in the prompt instructions is just a format example, not related to ACI questions. 3. **Empty lists**: Both `merchant_category_code: []` and `aci: []` mean "this dimension is not constrained to any specific value" — skip these rules when iterating over MCCs/ACIs specifically. 4. **is_credit filtering for ACI questions**: Include rules with `is_credit=None` (applies to all), not just `is_credit=True`. 5. **Tie-breaking for ACI**: When multiple ACIs have the same maximum fee, return the one that comes first alphabetically.