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- #include <bits/stdc++.h>
- using namespace std;
- const int MOD = 998244353;
- long long int fp(long long int a, long long int b) {
- long long int res = 1;
- while(b) {
- if(b & 1)
- (res *= a) %= MOD;
- (a *= a) %= MOD;
- b >>= 1;
- }
- return res;
- }
- int main()
- {
- long long int N;
- cin >> N;
- vector<long long int> A(N + 1), dp(N + 1), sum(N + 1);
- long long int inv = fp(N, MOD-2);
- for (int i = 1; i <= N; i++) {
- cin >> A[i];
- }
- for (int i = 0; i < N; i++) {
- dp[i + 1] = (sum[i] * inv + inv) % MOD;
- sum[i + 1] = (sum[i] + dp[i + 1]) % MOD;
- }
- long long ans = 0;
- for (int i = 1; i <= N; i++) {
- ans = (ans + dp[i] * A[i]) % MOD;
- }
- cout << ans << endl;
- }
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