BitSet排序一億個數字

一億個數字排序，數字範圍2億以內

        long begin = System.currentTimeMillis();
        BitSet set = new BitSet(100000000);
        for (int i=1000000000; i>0; i--) {
            if ((i&1)==0) {
                set.set(i<<1);
            } else {
                set.set(i);
            }
        }
        long end = System.currentTimeMillis();
        System.out.println(end - begin);
        System.out.println(set.length());


        OUTPUT:
            5391
            2000000001