class Dec2XXX
{
    public static void main(String[] args)
    {
        toBin(6);
        toHex(6);
        toOct(6);
    }

    /*10to2*/
    public static void toBin(int num)
    {
        trans(num, 1, 1);
    }
    /*10to16*/
    public static void toHex(int num)
    {
        trans(num, 15, 4);
    }
    /*10to8*/
    public static void toOct(int num)
    {
        trans(num, 7, 3);
    }
  //抽取相同功能
    public static void trans(int num, int base, int offset)
    {
        //查表法
        char[] chs = new char[]{'0','1','2','3',
                                '4','5','6','7',
                                '8','9','A','B',
                                'C','D','E','F'};
        //用于存储转换结果 int类型 最大32位
    char[] arr = new char[32];
        int pos = arr.length;

        //只进行有效位的转换
        while(num != 0)
        {
      //位运算
            int temp = num & base;
            arr[--pos] = chs[temp];
            num = num >>> offset;//无符号右移
        }
     
    //"int pos = arr.length;"以及"arr[--pos]"的目的是使下面的for循环的i = pos
        for(int i = pos; i < arr.length; i++)
        {
            System.out.print(arr[i]);
        }
    }
}

 posted on 2014-10-22 22:25  zhangbz  阅读(197)  评论(0编辑  收藏  举报