第三次作业

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)

import java.util.Scanner;
public class ydy {

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.

import java.util.Scanner;
public class ydy {
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 )
        x*2 –1 ( x < 0 )

 1 package tset;
 2 import java.util.Scanner;
 3 public class demo {
 4     public static void main(String[] args) {
 5         Scanner input = new Scanner(System.in);
 6         System.out.println("请输入x的值(整数):");
 7         int x = input.nextInt();
 8         int y;
 9         if(x > 0) {
10             y = x + 3;
11             System.out.println("y的值是:" + y);
12         }else if(x == 0) {
13             System.out.println("y的值是:0");
14         }else if(x < 0) {
15             y = x * x - 1;
16             System.out.println("y的值是:" + y);
17         } 
18 
19     }
20 
21 }

 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)
请在博客园班级提交,截止时间下周三中午12点.

import java.util.Scanner;
public class ydy {
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");
}
}
}