第三次java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 demo01;
import java.util.Scanner;
public class demo001 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.print("请输入年份：");
        int leap = input.nextInt();
        if(((leap%4 == 0) && (leap%100 != 0)) || (leap%400 == 0)){
            System.out.print(leap+"是闰年");
        }
        else{
            System.out.print(leap+"不是闰年");
        }
    }

}

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 demo01;
import java.util.Scanner;
public class demo001 {

    public static void main(String[] args) {
        Scanner input=new Scanner(System.in);
        System.out.println("请输入四位会员卡号");
        int a=input.nextInt();
        switch(a%1000/100) {
        case 3:
        case 6:
        case 9:
            System.out.println("幸运会员");break;
        default:
            System.out.println("不是幸运会员");break;
        }
    }
}

.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 ) x2 –1 ( x < 0 ) 

package demo01;
import java.util.Scanner;
public class demo001 {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.println("输入x:");
        int x = input.nextInt();   
        if (x>0) {
           System.out.println("y="+(x+3));
       }else if (x<0) {
           System.out.println("y="+(x*2-1));
       }else {
           System.out.println("y=0");
       }

    }
}

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 demo01;
import java.util.Scanner;
public class demo001 {

    public static void main(String[] args) {
        Scanner input=new Scanner(System.in);
           System.out.println("请输入三个数");
           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("能够成三角形");
           else
               System.out.println("不能构成三角形");
       }

    }