java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 Text;

import java.util.Scanner;

public class zuoye2 {
    public static void main(String[] args) {
        Scanner sc= new Scanner(System.in);
        int year = sc.nextInt();
        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");
            }
    }    
}

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 Text;

import java.util.Scanner;

public class zuoye2 {
    public static void main(String[] args) {
        Scanner sc= new Scanner(System.in);
        System.out.println("请输入4位会员卡号：");
        int num= sc.nextInt();
        if(num/100%10%3==0) {
            System.out.println(num+"是幸运会员");
            }else {
                System.out.println(num+"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 )
x2 –1 ( x < 0 )

package Text;
import java.util.Scanner;

public class zuoye2 {
    public static void main(String[] args) {
        Scanner sc= new Scanner(System.in);
        System.out.println("请输入x值：");
        double x= sc.nextDouble();
        if(x>0) {
            System.out.println("y=x+3="+(x+3));
            }else if(x==0){
                System.out.println("y="+x);
            }else {
                System.out.println("y=x*x-1="+(x*x-1));
            }
    }    
}

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 Text;
import java.util.Scanner;
public class zuoye2 {
    public static void main(String[] args) {
        Scanner sc= new Scanner(System.in);
        System.out.println("请输入第一个数：");
        double x= sc.nextDouble();
        System.out.println("请输入第二个数：");
        double y= sc.nextDouble();
        System.out.println("请输入第三个数：");
        double z= sc.nextDouble();
        double i=x+y;
        double h=x+z;
        double l=y+z;
        if(x>=l || y>=h || z>=i) {
            System.out.println("不能构成三角形");
        }else {
            System.out.println("能构成三角形");
        }
    }    
}