有道难题

#include <iostream>
using namespace std;

const unsigned char daos_in_a_byte[2] = {
    0x84, //10000100
    0x21  //00100001
}; 
const unsigned char daos_in_a_byte_mask[2] = {
    0xFC, //11111100
    0x3F  //00111111
};
const unsigned short daos_in_a_word[2] = {
    0x4008, //00001000_01000000
    0x1002  //00000010_00010000
}; 
const unsigned short daos_in_a_word_mask[2] = {
    0xC00F, //00001111_11000000
    0xF003  //00000011_11110000
};

int count_in_byte(const unsigned char byte)
{
    return ((byte & daos_in_a_byte_mask[0]) == daos_in_a_byte[0]) ||
            ((byte & daos_in_a_byte_mask[1]) == daos_in_a_byte[1]);
}

int count_in_word(const unsigned short word)
{
    return ((word & daos_in_a_word_mask[0]) == daos_in_a_word[0]) ||
            ((word & daos_in_a_word_mask[1]) == daos_in_a_word[1]);
}

int count_dao(const unsigned char* str)
{
    int result = 0;
    for (int i = 0; *(str + i) != 0; ++i)
    {
        result += count_in_byte(*(str + i));
        if (*(str + i + 1) != 0)
        {
            result += count_in_word(*(const unsigned short * )(str + i));
        }
    }
    return result;
}

int main(int argc, char** argv) {
    char* str1 = "www.youdao.com";
    char* str2 = "dict.youdao.com";
    cout << count_dao((const unsigned char * )str1) << endl;
    cout << count_dao((const unsigned char * )str2) << endl;
    return 0;
}