getprime.java

算出数的素数因子的算法

import java.io.*;
public class GetPrime {
     public static void main ( String args[ ]){
     int a = 0;
     String s; 	
     try{
         System.out.print("请输入一个自然数:");
         BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); 
         s = br.readLine();
         a = Integer.parseInt(s);
     }catch(IOException e){}
     System.out.println("素数因子为:");
loop: for(int i=1; i<=a; i++){
          for(int j=2;j<=Math.sqrt(i);j++)
	     if(i%j==0) continue loop;
                if(a%i==0){
		  System.out.print(i+"\t");
                }
             }   
    
     }
}