//使用java提供的方法
  //但僅局限于比較常用的二進(jìn)制、八進(jìn)制、十六進(jìn)制
  public static String trans1(int num, int radix)
  {
    if(radix == 2)
      return Integer.toBinaryString(num);
    else if(radix == 8)
      return Integer.toOctalString(num);
    else if(radix == 16)
      return Integer.toHexString(num);

    return null;
  }

//使用數(shù)組的形式進(jìn)行轉(zhuǎn)換
  public static void trans2(int num, int radix)
  {
    System.out.println(num+"轉(zhuǎn)成"+radix+"進(jìn)制數(shù)為：");

    //創(chuàng)建數(shù)組，32位
    char[] arr = new char[32];

    //創(chuàng)建參考字符數(shù)組
    char[] ch = {
      '0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'
    };

    //指針，從數(shù)組最后開始
    int pos = 32;

    //開始循環(huán)計(jì)算num和radix的商和余數(shù)
    while(num > 0)
    {
      arr[--pos] = ch[num % radix];
      num /= radix;

      /*
       * 這里是針對(duì)二進(jìn)制、八進(jìn)制和十六進(jìn)制進(jìn)行的移位運(yùn)算
      arr[--pos] = ch[num&(radix-1)];
      if(radix == 2)
        num >>= 1;
      else if(radix == 8)
        num >>= 3;
      else if(radix == 16)
        num >>= 4;
      */
    }

    //輸出有效的進(jìn)制數(shù)
    for(int i = pos; i < 32; i++)
      System.out.print(arr[i]);

    System.out.println();
  }

//使用StringBuilder進(jìn)行轉(zhuǎn)換
  public static String trans3(int num, int radix)
  {
    //使用StringBuilder的reverse方法
    StringBuilder sb = new StringBuilder();

    while(num > 0)
    {
      //把除以基數(shù)的余數(shù)存到緩沖區(qū)中
      sb.append(num % radix);
      num /= radix;
    }

    return sb.reverse().toString();
  }