count_bits_flip.cpp

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#include <cassert>   
#include <cstdint>
#include <iostream>  
namespace bit_manipulation {
namespace count_bits_flip {
std::uint64_t countBitsFlip(
    std::int64_t A,
    std::int64_t B) {  // int64_t is preferred over int so that
                       // no Overflow can be there.
 
    int count =
        0;  // "count" variable is used to count number of bits flip of the
            // number A to form B in binary representation of number 'n'
    A = A ^ B;
    while (A) {
        A = A & (A - 1);
        count++;
    }
    return count;
}
}  // namespace count_bits_flip
}  // namespace bit_manipulation
 
static void test() {
    // A = 10, B = 20 return 4
    assert(bit_manipulation::count_bits_flip::countBitsFlip(10, 20) == 4);
    // A = 20, B = 25 return 3
    assert(bit_manipulation::count_bits_flip::countBitsFlip(20, 25) == 3);
    // A = 7, B = 10 return 3
    assert(bit_manipulation::count_bits_flip::countBitsFlip(7, 10) == 3);
    // A = 17, B = 25 return 1
    assert(bit_manipulation::count_bits_flip::countBitsFlip(17, 25) == 1);
    // A = 11, B = 8 return 2
    assert(bit_manipulation::count_bits_flip::countBitsFlip(11, 8) == 2);
    // A = 21, B = 22 return 2
    assert(bit_manipulation::count_bits_flip::countBitsFlip(21, 22) == 2);
    // A = 7, B = 786 return 5
    assert(bit_manipulation::count_bits_flip::countBitsFlip(7, 786) == 5);
    std::cout << "All test cases successfully passed!" << std::endl;
}
int main() {
    test();  // run self-test implementations
    return 0;
}