位数组上的快速 AND 运算

Question

What can be a faster algorithm for doing bitwise AND operation on large bit-arrays? I have implemented bit-array in C++ using a char array. For now, I am iterating over each byte and performing AND operation.

void ANDoperation(char* A, char* B){
  for (int i=0; i<(array_size/8 +1); i++ ){
    A[i] &= B[i];
  }
}

For K arrays, I am executing this function iteratively K-1 times.

Answer 1

If you would like to go for a more C++-ish way, I would suggest you using std::bitset in a following manner:

#include <iostream>
#include <bitset>

int main()  {
    std::bitset<3> v1(0b110);
    std::bitset<3> v2(0b011);

    v1 &= v2;

    std::cout << v1.to_string() << std::endl; // 010

    return 0;
}

Demo

or as @AndrewBainbridge suggested:

void and_operation(std::bitset<3000>& v1, std::bitset<3000> const& v2) {
    v1 &= v2;
}