Map Order User IDs to Customer Names
Crunchyroll● MediumFULLTIMEPHONE SCREENProblem statement
Three two-dimensional string arrays describe customer purchases, orders and products. Each customer buys one kind of product.
customers:[name,email,productName,quantity].orders:[userId,email,totalAmount]; an order email may be missing.products:[productName,unitPrice].
Return a mapping from each order user ID to a customer name using the following practice rules.
- For this exercise, assume a present order email matches the customer with exactly that email. Compare complete strings case-sensitively. The amount does not change this email match, and an unknown present email does not use fallback matching.
- For this exercise, assume a missing email is represented by an empty string. Compare the order amount with each customer’s
quantity × unitPrice. Resolve the name only when exactly one customer row has that amount. - For this exercise, assume unmatched or ambiguous orders resolve to an empty name. Two matching customer rows remain ambiguous even if their names are the same.
For this exercise, return a two-column string array [userId,resolvedName] with one row per order, in the original order sequence. Quantities and prices are exact base-10 integer strings; prices and amounts use the same smallest currency unit. Leading zeros do not change a number.
Function
mapOrderNames(customers: String[][], orders: String[][], products: String[][]) → String[][]Examples
Example 1
customers = [["Ada", "ada@example", "Book", "2"], ["Ben", "ben@example", "Pen", "3"]]orders = [["u1", "ada@example", "7"], ["u2", "", "600"], ["u3", "absent@example", "600"]]products = [["Book", "500"], ["Pen", "200"]]return = [["u1", "Ada"], ["u2", "Ben"], ["u3", ""]]This authored example uses a known email independently of amount, a unique missing-email subtotal, and an unknown present email that does not fall back.
Example 2
customers = [["Ada", "a", "Book", "2"], ["Ben", "b", "Game", "1"]]orders = [["u1", "", "1000"], ["u2", "a", "1000"]]products = [["Book", "500"], ["Game", "1000"]]return = [["u1", ""], ["u2", "Ada"]]This authored missing-email order has two matching customer rows, while its known-email sibling identifies Ada.
Example 3
customers = []orders = [["u1", "", "0"]]products = []return = [["u1", ""]]This authored order has no customer candidate; keep its user ID with an empty name.
Constraints
- For this exercise, assume each table contains 0 through 100 rows with exactly its stated number of columns.
- For this exercise, assume product names, customer emails and order user IDs are unique within their respective tables. Every customer product name exists in
products. - For this exercise, assume quantity and unit price are in
[1,10^6], and order amount is in[0,10^12]. Numeric strings contain only base-10 digits and have at most 13 characters. - For this exercise, assume names and identifiers are nonempty printable ASCII strings of at most 50 characters; only a missing order email is empty.