第三周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 tset;
import java.util.Scanner;
public class demo {

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

    }

}

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 tset;
import java.util.Scanner;
public class demo {
    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();
         if ((a % 1000 / 100) % 3 == 0 ) {
             System.out.println("是幸运会员");
             } else {
                System.out.println("不是幸运会员");
             }
        // TODO Auto-generated method stub

    }

}

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 tset;
import java.util.Scanner;
public class demo {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.println("请输入x的值(整数):");
        int x = input.nextInt();
        int y;
        if(x > 0) {
            y = x + 3;
            System.out.println("y的值是:" + y);
        }else if(x == 0) {
            System.out.println("y的值是:0");
        }else if(x < 0) {
            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 tset;
import java.util.Scanner;
public class demo {
    public static void main(String[] args) {
         Scanner input = new Scanner(System.in);
            System.out.println("请输入三角形的三边(整数):");
            int a = input.nextInt();      
            int b = input.nextInt();
            int c = input.nextInt();
            int d = a + b;  
            int e = a + c;
            int f = b + c;
            if(d > c && e > b && f > a) {
                System.out.println("能构成三角形");
            } else {
                System.out.println("不能构成三角形");            
            }            
    }
}