题解 | 取近似值

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);
        double a = in.nextDouble();
        if (a - (int)a >= 0.5) { //判断是否四舍五入
            double ceil = Math.ceil(a);//获取向上取整的值
            int i = (int) ceil;
            System.out.println(i);
        } else { //判断是否四舍五入
            double floor = Math.floor(a);
            int i = (int) floor;
            System.out.println(i);
        }
    }
}