小编Gia*_*omo的帖子

我需要验证字节数组（即，字符）中的位是否是相同类型的另一个数组的子集：例如，0001.0011（19）是0011.0011（51）的子集，而0000.1011（11）不是。

我开始玩按位运算，几乎用XOR / OR / XOR序列解决了它：

int is_subset (char *set_a, char *set_b, int size)
{
  /* The operation is performed with three bitwise operations, resulting in a
   * sequence of bits that will be equal to zero if set_a is a subset of
   * set_b. As a bonus, the positions where the sets differ will be
   * available in the resulting sequence, and thus the number of differing
   * positions can be obtained by counting the number of bits set …