public class BitSet implements Cloneable, java.io.Serializable 
{
 private final static int ADDRESS_BITS_PER_WORD = 6;
 private final static int BITS_PER_WORD = 1 << ADDRESS_BITS_PER_WORD;
 private final static int BIT_INDEX_MASK = BITS_PER_WORD - 1;
 /* Used to shift left or right for a partial word mask */
 private static final long WORD_MASK = 0xffffffffffffffffL;
 private static final ObjectStreamField[] serialPersistentFields =
    {
     new ObjectStreamField("bits", long[].class),
}
;
/**
   * The internal field corresponding to the serialField "bits".
   */
private long[] words;
.....
}

public BitSet() 
{
    initWords(BITS_PER_WORD);
    sizeIsSticky = false;
}

public BitSet(int nbits)
   {
    // nbits can't be negative; size 0 is OK
    if (nbits < 0)
      throw new NegativeArraySizeException("nbits < 0: " + nbits);
    initWords(nbits);
    sizeIsSticky = true;
  }

public class Alibaba
{
 public static void main(String[] args)
   {
  Random random=new Random();
  List<Integer> list=new ArrayList<>();
  for (int i=0;i<10000000;i++)
      {
   int randomResult=random.nextint(100000000);
   list.add(randomResult);
  }
  System.out.println("产生的随机数有");
  for (int i=0;i<list.size();i++)
      {
   System.out.println(list.get(i));
  }
  BitSet bitSet=new BitSet(100000000);
  for (int i=0;i<10000000;i++)
      {
   bitSet.set(list.get(i));
  }
  System.out.println("0~1亿不在上述随机数中有"+bitSet.size());
  for (int i = 0; i < 100000000; i++)
      {
   if(!bitSet.get(i))
         {
    System.out.println(i);
   }
  }
 }
}