第一次实训作业 

 1 public class jiou{
 2 
 3     public static void main(String[] args) {
 4      
 5         int a=5;
 6           if(a%2==0)
 7           {
 8               System.out.println("a是偶数");
 9              
10           }
11           else{
12               System.out.println("a是奇数");
13           }
14     }
15 
16 }

2.

 1 import java.util.*;
 2 public class yuan{
 3     public static void main(String[] args) {
 4       
 5        Scanner reader =new Scanner(System.in) ;
 6        double r,s ;
 7        final double pi=3.1415;
 8        System.out.println("输入圆的半径");
 9        r=reader.nextDouble();
10        s=pi*r*r;
11        System.out.println("圆的面积="+s);
12        
13     }
14 
15 }

3.

 1 import java.util.*;
 2   public class jiami {
 3  
 4       public static void main(String[] args) {
 5           
 6             Scanner in =new Scanner(System.in);
 7             int a;
 8             a=sc.netxInt();
 9           System.out.println((int)((a*10+5)/2+3.14159));
10     }
11  
12  }

4.

 1 public class ji {
 2 
 3      public static void main(String[] args) {
 4         final int zongshu = 100;
 5          final int qian = 100;
 6         for(int i = 0; i<=20; i++)
 7         for(int j = 0; j<=33; j++)
 8         for(int k = 0; k<=300; k=k+3)
 9           if(i*5+j*3+k/3 ==qian && i+j+k == zongshu)
10                     {
11                         System.out.println("公鸡:"+i);
12                         System.out.println("母鸡:"+j);
13                        System.out.println("公鸡:"+k);
14                       }
15 }
16 }

5.

 1 public class paixu {
 2   
 3       public static void main(String[] args) {
 4           int a;
 5           int b = 0;
 6           for(int i = 1; i<=4; i++)
 7        
 8              for(int j =1; j<=4; j++)
 9          
10                  for(int k = 1; k<=4; k++)
11                 
12                      if(i != j && i != k && j!=k)
13                      {
14                         b++;
15                          a = i*100+j*10+k;
16                         System.out.println(a);
17                      }
18                                
19           }
20              
21       }

6.

 

 1 import java.util.*;
 2 public class sushu {
 3     public static void main(String[] args) {
 4         int i=0;
 5         Scanner reader = new Scanner(System.in);
 6         int num;
 7         num=reader.nextInt();
 8         for(i=2;i<num;i++) {
 9             if(num%i==0)
10                 break;
11             if(num==i)
12                 System.out.println(num+"为素数");
13             else
14                 System.out.println(num+"不是素数");
15                 
16         }

 

posted @ 2019-04-06 18:47  拒绝吃土  阅读(146)  评论(0)  编辑  收藏  举报