#include <iostream>
#include <vector>

bool isVectorEmpty(const std::vector<unsigned char>& vec) {
    for (const auto& ch : vec) {
        if (ch != '\0') {
            return false;
        }
    }
    return true;
}

int main() {
    std::vector<unsigned char> vec1 = {'\0', '\0', '\0'};
    std::vector<unsigned char> vec2 = {'\0', 'A', '\0'};
    
    if (isVectorEmpty(vec1)) {
        std::cout << "vec1 is empty." << std::endl;
    } else {
        std::cout << "vec1 is not empty." << std::endl;
    }
    
    if (isVectorEmpty(vec2)) {
        std::cout << "vec2 is empty." << std::endl;
    } else {
        std::cout << "vec2 is not empty." << std::endl;
    }
    
    return 0;
}

vec1 is empty.
vec2 is not empty.