func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long mod = 998244353;   map<tuple<unsigned long, int, int>, pair<long long, long long> > m;   pair<long long, long long> zml(long long x, bitset<10> s, int p, int k,                                  bool limit) {     if (int(s.count()) > k) return {0, 0};     if (p == -1) return {1, 0};     if (s.count() == 1 && s[0]) s.reset();     if (!limit && m.count({s.to_ulong(), p, k})) return m[{s.to_ulong(), p, k}];     long long r = 1;     for (int i = 0; i < p; i++) r *= 10;     long long y = x / r;     long long ret1 = 0;     long long ret2 = 0;     for (int i = 0; i <= y; i++) {       bitset<10> t = s;       t[i] = 1;       pair<long long, long long> z =           zml(i == y ? x - y * r : r - 1, t, p - 1, k, limit && i == y);       ret1 += z.first;       ret1 %= mod;       ret2 += z.second;       ret2 %= mod;       ret2 += z.first * (((r % mod) * i) % mod);       ret2 %= mod;     }     if (!limit)       return m[{s.to_ulong(), p, k}] = {ret1, ret2};     else       return {ret1, ret2};   }   int main() {     long long l, r;     int k;     cin >> l >> r >> k;     cout << (zml(r, bitset<10>(), 18, k, 1).second -              zml(l - 1, bitset<10>(), 18, k, 1).second + mod) %                 mod          << endl;   }   