Интересные числа

// 1 group + 6 points XD https://informatics.mccme.ru/mod/statements/view3.php?id=18806&chapterid=113102#1

# include <iostream>
# include <vector>
using namespace std;
const uint64_t MOD = 1000000007;
int main() {
    uint64_t l, r;
    cin >> l >> r;
    uint64_t i = l;
    uint64_t count = 0;
    while (i <= r) {
        uint64_t new_i = i;
        if ((i >= 10 && i % 10 < (i % 100) / 10) || i % 10 == 0) {
            new_i = 0;
            vector<int8_t> copy;
            while (i > 9) {
                copy.push_back(i % 10);
                i /= 10;
            }
            copy.push_back(i);
            for (size_t j = copy.size() - 2; (j + 1) > j; j--) {
                if (copy[j] < copy[j + 1]) {
                    copy[j] = copy[j + 1];
                }
            }
            for (size_t j = copy.size() - 1; (j + 1) > j; j--) {
                new_i = new_i * 10 + copy[j];
            }
        }
        if (new_i >= l && new_i <= r) {
            count++;
        }
        i = new_i + 1;
    }
    cout << count % MOD;
    return 0;
}