质因数的求解

public class Factor {

    static void   prim(int m, int n,ArrayList a) {
        if(m>=n) {
          while(m%n != 0) n++; //除数不断增加，直到能除开
          m /= n;              //变成新的被除数
          a.add(n);
          //System.out.println(n);
          prim(m, n,a);
        }
    }

    public static void main(String[] args)
    {
        int m =42;
        int n =2; //初始的除数
        ArrayList a = new ArrayList();
        prim(m,2,a);

        Iterator it = a.iterator();
        System.out.println("所有的因子为：" );
        while(it.hasNext())
        {
            System.out.print(it.next() + "  ");
        }
    }
}