func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long mod = 998244353;   pair<long long, long long> dp[20][1 << 10];   int a[20];   long long pw[20];   int change(long long n) {     int cnt = 0;     while (n) {       if (n & 1) cnt++;       n /= 2;     }     return cnt;   }   int k;   long long pow(int e, int n) {     long long ans = 1;     while (n--) {       ans *= e;     }     return ans;   }   pair<long long, long long> dfs(int len, long long Set, bool zero, bool limit) {     if (len == 0) {       if (change(Set) <= k) return make_pair(1, 0);       return make_pair(0, 0);     }     if (!limit && dp[len][Set].first != 0 && !zero) return dp[len][Set];     int u = limit ? a[len - 1] : 9;     pair<long long, long long> ans = make_pair(0, 0);     for (int i = 0; i <= u; i++) {       pair<long long, long long> tem = make_pair(0, 0);       if (change(Set | (1 << i)) > k) continue;       if (zero && i == 0)         tem = dfs(len - 1, Set, zero, i == u && limit);       else {         tem = dfs(len - 1, Set | (1 << i), zero && i == 0, i == u && limit);       }       ans.first += tem.first;       ans.first %= mod;       ans.second =           (ans.second + i * tem.first % mod * pw[len - 1] % mod + tem.second) %           mod;     }     if (!limit && !zero) dp[len][Set] = ans;     return ans;   }   void init() {     pw[0] = 1;     for (int i = 1; i < 20; i++) pw[i] = (pw[i - 1] * 10) % mod;     for (int i = 0; i < 20; i++)       for (int j = 0; j < 1 << 9; j++) dp[i][j].first = dp[i][j].second = 0;   }   long long solve(long long n) {     int len = 0;     init();     while (n) {       a[len++] = n % 10;       n /= 10;     }     return dfs(len, 0, 1, 1).second;   }   int main() {     long long l, r;     while (cin >> l >> r >> k) {       cout << (solve(r) - solve(l - 1) + mod) % mod << endl;     }     return 0;   }   