func_code_string: #include <bits/stdc++.h>   using namespace std;   static long long mod = 998244353;   long long pow(long long x, long long y) {     x = x % mod;     int res = 1;     while (y > 0) {       if (y & 1) {         res = (res * x) % mod;       }       y = y >> 1;       x = (x * x) % mod;     }     return res;   }   long long modInverse(long long n, long long mod) { return pow(n, mod - 2); }   long long nCrmodFermat(long long n, long long r) {     if (r == 0) return 1;     long long fact[n + 1];     fact[0] = 1;     for (long long i = 1; i <= n; i++) {       fact[i] = ((fact[i - 1] % mod) * (i % mod)) % mod;     }     return (fact[n] * modInverse(fact[r], mod) % mod *             modInverse(fact[n - r], mod) % mod) %            mod;   }   int main() {     long long n;     cin >> n;     vector<long long> v(2 * n);     long long sum = 0;     for (int i = 0; i < 2 * n; i++) {       cin >> v[i];     }     sort(v.begin(), v.end());     int i = 0;     int j = (2 * n) - 1;     while (i < n && j >= n) {       sum = (sum + abs(v[i] - v[j])) % mod;       i++;       j--;     }     cout << ((sum % mod) * (nCrmodFermat((2 * n), n) % mod)) % mod << endl;     return 0;   }   