蓝桥杯_入门训练_圆的面积(四舍五入保留七位小数)

import java.util.*;
public class Main {
    public static void main(String[] args){
        Scanner sc= new Scanner(System.in);
        int r=sc.nextInt();
        double s = Math.PI*r*r;
        System.out.println(String.format("%.7f",s));
    }
}

 

转载于:https://www.cnblogs.com/huangming-zzz/p/10424507.html