啊？

#include <iostream>
#include <vector>
#include <algorithm>

bool isValid(const std::vector<int>& digits, int n) {
    std::vector<int> a(digits);
    std::sort(a.begin(), a.end());
    int sum = 0;
    for (int i = 0; i < 5; ++i) {
        sum = sum * 10 + a[i];
    }
    return sum % n == 0;
}

void printAnswer(int n) {
    for (int b1 = 0; b1 < 10; ++b1) {
        for (int b2 = b1 + 1; b2 < 10; ++b2) {
            for (int b3 = b2 + 1; b3 < 10; ++b3) {
                for (int b4 = b3 + 1; b4 < 10; ++b4) {
                    for (int b5 = b4 + 1; b5 < 10; ++b5) {
                        std::vector<int> b = {b1, b2, b3, b4, b5};
                        std::sort(b.begin(), b.end());

                        int a = n * (b[0] * 10000 + b[1] * 1000 + b[2] * 100 + b[3] * 10 + b[4]);
                        std::vector<int> aDigits = {a / 10000, a / 1000 % 10, a / 100 % 10, a / 10 % 10, a % 10};

                        if (isValid(aDigits, n)) {
                            std::cout << std::string(aDigits.begin(), aDigits.end()) << " / "
                                      << std::string(b.begin(), b.end()) << std::endl;
                        }
                    }
                }
            }
        }
    }
}

int main() {
    int n;
    std::cin >> n;
    if (n >= 2 && n <= 79) {
        printAnswer(n);
    } else {
        std::cout << "No answer." << std::endl;
    }
    return 0;
}