package diyici;
import java.util.*;

public abstract class diyici {

     public static void main(String[] args) {
            // TODO Auto-generated method stub
             
            Scanner input=new Scanner(System.in);
            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");
            }
                 
            }
             

package diyici;
import java.util.*;

public abstract class diyici {
     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");
       }
   }
             

    }

package diyici;
import java.util.*;

public abstract class diyici {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input=new
        Scanner (System.in);
        System.out.println("请输入x的值：");
        int x=input.nextInt();
        int y=0;
        if(x>0){
            y=x+3;
        }else if(x==0){
            y=0;
        }else{
            y=x*2-1;
        }
        System.out.println("y="+y);
         
    }
 
}

package diyici;
import java.util.*;

public abstract class diyici {
     public static void main(String[] args) {
            Scanner AA = new Scanner(System.in);
            System.out.println("输入三个正整数");
            int a = AA.nextInt();
            int b = AA.nextInt();
            int c = AA.nextInt();
            if (a<=0||b<=0||c<=0){
            System.out.println("输入错误，请重新输入");
            }else 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");
            }
}