第三周作业

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 chap1;

import java.util.Scanner;

public class Main
{
    public static void main(String[] args)
    {
        System.out.println("请输入年份");
        Scanner s = new Scanner(System.in);
        int year = s.nextInt();
        if (year < 0)
        {
            System.out.println("年份不合法");
            return;
        }
        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 chap1;

import java.util.Scanner;

public class Main
{
    public static void main(String[] args)
    {
        System.out.println("请输入四位会员卡号");
        Scanner s = new Scanner(System.in);
        int card = s.nextInt();
        if (card >= 10000 || card < 1000)
        {
            System.out.println("输入的位数不正确");
            return;
        }
        int bai = card / 100 % 10;
        if (bai % 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 chap1;

import java.util.Scanner;

public class Main
{
    public static void main(String[] args)
    {
        System.out.println("请输入X的值");
        Scanner s = new Scanner(System.in);
        int x = s.nextInt();
        int y = 0;
        if (x > 0)
        {
            y = x + 3;
        }
        else if (x < 0)
        {
            y = x * 2 - 1;
        }
        System.out.println("y的值为" + 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 chap1;

import java.util.Scanner;

public class Main
{
    public static void main(String[] args)
    {
        System.out.println("请输入三条边");
        Scanner s = new Scanner(System.in);
        int a = s.nextInt();
        int b = s.nextInt();
        int c = s.nextInt();
        if (a + b > c || a + c > b || b + c > a)
        {
            System.out.println("能构成三角形");
        }
        else
        {
            System.out.println("不能构成三角形");
        }
    }
}