Question

Is there any clever way to mix two bit sequences in such way that bits from first sequence will be on odd places, and bits from second sequence will be on even places.
Both sequences are no longer than 16b so output will fit into 32bit integer.

例:

First sequence  : 1   0   0   1   0   0  
Second sequence :   1   1   1   0   1   1  
Output          : 1 1 0 1 0 1 1 0 0 1 0 1

我设想将体积2^16成群,然后产出如下:

arr[first] << 1 | arr[second]

Answer 1

查阅该页列出了显而易见的(就循环而言)和优化的3项算法。两者都不是特别简单,而没有测试,我就认为其速度远远快于 lo。

Answer 2

C#:

public Int32 Mix(Int16 b1, Int16 b2)
{
  Int32 res = 0;
  for (int i=0; i<16; i++)
  {
    res |= ((b2 >> i) & 1) << 2*i;
    res |= ((b1 >> i) & 1) << 2*i + 1;
  }
  return res;
}

友情链接