第二次作业

1.输入一个年份,判断是不是闰年(能被4整除但不能被100整除,或者能被400整除)

package xs;

import java.util.Scanner;

public class hd {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int year=2010;
        Scanner scan =new Scanner(System.in);
        System.out.println("输入一个年份:");
        if(scan.hasNext()){
            String str1=scan.next();
            try{
                year=Integer.parseInt(str1);
            }catch(NumberFormatException e){
                System.out.println("输入错误!");
            }
            if((year%4==0&&year%100!=0)||(year%400==0)){
                System.out.println(year+"是闰年");
            }
            else{
                System.out.println(year+"不是闰年");
            }
        }
        scan.close();  
    }

}

2.输入一个4位会员卡号,如果百位数字是3的倍数,就输出是幸运会员,否则就输出不是.

package xs;

import java.util.Scanner;

public class hd {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input=new Scanner(System.in);
        System.out.println("请输入四位卡号:");
        int x=input.nextInt();
        if((x%1000/100)%3==0){
            System.out.println("是幸运会员");
        }else{
            System.out.println("不是幸运会员");
        }
    }

}

3.已知函数,输入x的值,输出对应的y的值.
        x + 3 ( x > 0 )
        y =  0 ( x = 0 )
        x*2 –1 ( x < 0 )

package xs;
import java.util.Scanner;
public class hd {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        System.out.println("请输入x的值：");
        Scanner input=new Scanner(System.in);
        float x=input.nextInt();
        float y;
        if(x>0){
            y=x+3;
        }else if(x==0){
            y=0;
        }else{
            y=x*x-1;
        }
        System.out.println("y的值是"+y);
    }
}

4.输入三个数,判断能否构成三角形(任意两边之和大于第三边)

package xs;

import java.util.Scanner;

public class hd {
    
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        System.out.println("请输入三角形的三条边:");
        Scanner input=new Scanner(System.in);
        int a=input.nextInt();
        int b=input.nextInt();
        int c=input.nextInt();
        if ((a+b)>c&&(a+c)>b&&(b+c)>a){
            System.out.println("Yes");
            
        }
        else{
            System.out.println("No");
            
        }
    }
}