package org.com;

import java.util.Scanner;

public class Demo1 {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.print("计算圆的面积和周长：\n1.计算面积\n2.计算周长\n请选择：");
        int a = input.nextInt();
        System.out.println("请输入半径：");
        int b = input.nextInt();
        int c = mianji(b);
        int d = zhouchang(b);
        if (a==1) {
            mianji(a);
        }
        else if(a==2){
            zhouchang(a);
        }
        else {
            System.out.println("选择错误！");    
        }
    }
    
    public static int mianji(int x) {
        double mj = 3.14*x*x;
        System.out.println("圆的面积为："+mj);
        return x;
    }
    public static int zhouchang(int x) {
        double zch = 2*3.14*x;
        System.out.println("圆的周长为："+zch);
        return x;
    }
}