Payment Preference Resolver

Problem

Design PaymentPreferenceResolver to choose a payment type by combining its supported transaction amount with the preference order configured for a transaction category.

Requirements

Amount eligibility. A payment type is eligible exactly when the transaction amount is less than or equal to its registered inclusive maximum.
Category preferences. defineCategoryPreference stores the supplied payment types from most to least preferred for that category.
Preferred eligible type. Selection returns the first eligible type in the category's configured order.
No eligible type. Selection returns the empty string when every configured type is excluded.

API

Signature	Returns	Behavior
`PaymentPreferenceResolver()`	Not applicable	Creates an empty resolver.
`addPaymentType(paymentType: string, maximumAmount: integer)`	`void`	Adds one payment type and its amount limit.
`defineCategoryPreference(category: string, paymentTypes: string[])`	`void`	Adds one category and its preference order.
`selectPaymentType(amount: integer, category: string)`	`string`	Resolves one payment type for the amount and category.

Examples

Step	Operation	Result
1	`addPaymentType("UPI", 2000)`	`void`
2	`addPaymentType("NET_BANKING", 10000)`	`void`
3	`defineCategoryPreference("GROCERIES", ["UPI", "NET_BANKING"])`	`void`
4	`defineCategoryPreference("TRAVEL", ["NET_BANKING", "UPI"])`	`void`
5	`selectPaymentType(1500, "GROCERIES")`	`"UPI"`
6	`selectPaymentType(5000, "GROCERIES")`	`"NET_BANKING"`
7	`selectPaymentType(1500, "TRAVEL")`	`"NET_BANKING"`
8	`selectPaymentType(15000, "TRAVEL")`	`""`

Constraints

At most 100 payment types, 1000 categories, and 100000 total method calls occur per testcase.
Payment type and category names contain from 1 through 64 Unicode code points and are compared exactly.
Amounts and maximum amounts are from 1 through 9000000000000000000.
A payment type is added once. A category is defined once, after all payment types are added.
Each category preference contains every registered payment type exactly once.
Selection uses a defined category. Inputs outside these preconditions are not judged.

Notes

Payment type and category names use the exact strings supplied during configuration. Calls are sequential, and concurrent access is outside scope.