题解 | #网购#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String strs = in.nextLine();
        String str[] = strs.split(" ");
        double nums[] = new double[str.length];
        double money=0;
        for (int i = 0; i < str.length; i++) {
            double num = Double.parseDouble(str[i]);
            nums[i] = num;
        }
        //双11有优惠劵
        if (nums[1] == 11 && nums[2] == 11 && nums[3] == 1) {
            money=nums[0] * 0.7 - 50;
            System.out.println(String.format("%.2f",money<0?0:money));
        }
        //双11没有优惠劵
        if (nums[1] == 11 && nums[2] == 11 && nums[3] == 0) {
            money=nums[0] * 0.7;
            System.out.println(String.format("%.2f",money<0?0:money));
        }
        //双12有优惠劵
        if (nums[1] == 12 && nums[2] == 12 && nums[3] == 1) {
            money=nums[0] * 0.8 - 50;
            System.out.println(String.format("%.2f",money<0?0:money));
        }
        //双12没有优惠劵
        if (nums[1] == 12 && nums[2] == 12 && nums[3] == 0) {
            money=nums[0] * 0.8;
            System.out.println(String.format("%.2f", money<0?0:money));
        }
        //其他
        if (nums[1] != 12 && nums[1] != 11 || nums[2] != 12 && nums[2] != 11) {
            System.out.println(String.format("%.2f",nums[0] ));
        }
    }
}