第一次实训作业

public class pro11 {

public static void main(String[] args) {
        int a=5;
        if(a%2==0) System.out.println("a是偶数");
        else System.out.println("a是奇数");
    }
}

 

 

import java.util.*;

public class pro12 {
    public static void main(String[] args) {
    Scanner read=new Scanner(System.in);
    final double PI=3.14;
    double r,s;
    System.out.println("输入圆的半径:");
    r=read.nextDouble();
    s=PI*r*r;
    System.out.println("圆的面积为:"+s);
    }
}

 

 

import java.util.*;

public class pro13 {
    public static void main(String[]args){
     Scanner get=new Scanner(System.in);
     int x;
     System.out.println("请输入需要加密的数:");
     x=get.nextInt();
     System.out.println("加密后的数是:"+(int)((x*10+5) / 2 + 3.14159));
    }
}