標準⼊⼒・変換・計算・出⼒を分ける p a r s e c a l c u l a t i o n / m a i n import fs from "node:fs"; type Item = { priceInYen: number; quantity: number }; const readInput = (): string => fs.readFileSync(0, "utf8"); const parseItems = (input: string): Item[] => { const numericValues = input.trim().split(" ").map(Number); const itemCount = numericValues[0]; return Array.from( { length: itemCount }, (_, itemIndex) => { const priceIndex = itemIndex * 2 + 1; const quantityIndex = itemIndex * 2 + 2; return { priceInYen: numericValues[priceIndex], quantity: numericValues[quantityIndex], }; }, ); }; const calculateTotalPriceInYen = (items: Item[]): number => items.reduce( (totalPriceInYen, item) => totalPriceInYen + item.priceInYen * item.quantity, 0, ); const main = () => { const rawInput = readInput(); const items = parseItems(rawInput); const totalPriceInYen = calculateTotalPriceInYen(items); console.log(totalPriceInYen); }; main();