CodeSprout 官方2026/10/04 00:19

官方解答 · 置頂Java

官方解答｜商品小計清單

CodeSprout 官方解答 · 題意分析、解題步驟與完整參考程式

import java.util.*;

public class Solution {
    private static class Item {
        final int category, price, quantity;
        Item(int[] row) { category=row[0]; price=row[1]; quantity=row[2]; }
        int original() { return price*quantity; }
    }
    private interface Pricing { int subtotal(Item item); }
    private static class Discount implements Pricing {
        public int subtotal(Item item) { return item.original()*90/100; }
    }
    private static class Regular implements Pricing {
        public int subtotal(Item item) { return item.original(); }
    }

    public static List<Integer> solve(int[][] items) {
        Pricing discount = new Discount(), regular = new Regular();
        List<Integer> values = new ArrayList<>();
        int originalTotal=0, finalTotal=0;
        int[] categoryTotals = new int[3];
        for (int[] row : items) {
            Item item = new Item(row);
            Pricing pricing = item.category == 2 ? discount : regular;
            int subtotal = pricing.subtotal(item);
            if (item.category != 2) subtotal *= 2;
            originalTotal += item.original(); finalTotal += subtotal;
            categoryTotals[item.category] += subtotal;
            values.add(subtotal);
        }
        return values;
    }
}