perfectnum.java

java 编程的一些简单例子

import java.io.*;
public class PerfectNum
{
public static void main(String args[])
{
   int i=0,t,q;
    String s;
   try{
	System.out.print("Please input int shu: ");
	BufferedReader br=
              new BufferedReader(new InputStreamReader(System.in));
	s=br.readLine();
	i=Integer.parseInt(s);
       }catch(IOException e) {}
    if (i%2==0)
	{i=i/2;
         System.out.print(" "+2);
         }
  for(int j=3;j<=i;j+=2)
     
      if(i%j!=0)
        continue;
       else
       {
             boolean flag=true;
             if   (j%2==0)
	     continue;
            else
	     { 
                for(q=3;q<j;q+=2)
		 { 
                   if(j%q==0)            
                    { flag=false ;
	  	    break;}
		  }
	      }
	         if(flag)
			System.out.print(" "+j);
            
        }
              	     
}
}