题解 | #计算商场折扣#

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner console = new Scanner(System.in);
        int price = console.nextInt();
        int cost = 0;

        //write your code here......
        if (price >= 5000) {
//             6折
            cost = (int) (price*0.6);
        } else if(price >= 2000 && price < 5000) {
//             7折
            cost = (int) (price*0.7);
        } else if(price >= 500 && price < 2000) {
//             8折
            cost = (int) (price*0.8);
        } else if(price >= 100 && price < 500){
//             9折
            cost = (int) (price*0.9);
        } else {
//             不打折
            cost = (int)price;
        }

        System.out.println(cost);
    }
}

double 转为 int ：

• (int)double 直接舍去小数。
• Math.round(double) 四舍五入
• Math.ceil(double) 向上取整
• Math.floor(doubel) 向下取整