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hi I got msgs from system that my solutions matches with some other people I was very curious so I check my solution and a solution of person from which my solution match according to system his user was byteplay_studios

his solution for C problem in edu round 174

include

include

using namespace std;

const int MOD = 998244353;

int main(){ ios::sync_with_stdio(false); cin.tie(nullptr);

int t;
cin >> t;


int maxExp = 200000 + 5;
vector<int> pow2(maxExp + 1, 0), inv2(maxExp + 1, 0);
pow2[0] = 1;
for (int i = 1; i <= maxExp; i++){
    long long tmp = (long long) pow2[i - 1] * 2;
    tmp %= MOD;
    pow2[i] = (int) tmp;
}

inv2[0] = 1;
const int invTwo = 499122177;
for (int i = 1; i <= maxExp; i++){
    long long tmp = (long long) inv2[i - 1] * invTwo;
    tmp %= MOD;
    inv2[i] = (int) tmp;
}

while(t--){
    int n;
    cin >> n;
    vector<int> a(n + 1);
    for (int i = 1; i <= n; i++){
        cin >> a[i];
    }


    vector<int> P(n + 1, 0);
    for (int i = 1; i <= n; i++){
        P[i] = P[i - 1] + (a[i] == 2);
    }


    vector<int> suff(n + 2, 0);
    for (int i = n; i >= 1; i--){
        int addVal = 0;
        if(a[i] == 3){
            addVal = pow2[P[i - 1]];
        }
        suff[i] = (suff[i + 1] + addVal) % MOD;
    }


    vector<int> suffCount3(n + 2, 0);
    for (int i = n; i >= 1; i--){
        suffCount3[i] = suffCount3[i + 1] + (a[i] == 3);
    }

    long long ans = 0;

    for (int i = 1; i <= n; i++){
        if(a[i] == 1){
            long long contribution = ((long long) suff[i + 1] * inv2[P[i]]) % MOD;
            contribution = (contribution - suffCount3[i + 1]) % MOD;
            if(contribution < 0)
                contribution += MOD;
            ans = (ans + contribution) % MOD;
        }
    }

    cout << ans % MOD << "\n";
}
return 0;

}

My solution

include

include

using namespace std;

const int M = 998244353; const int MX = 200005;

int main() { ios::sync_with_stdio(false); cin.tie(nullptr);

int t;
cin >> t;

vector<long long> p(MX);
vector<long long> ip(MX);

p[0] = 1;
for (int i = 1; i < MX; i++) {
    p[i] = (p[i - 1] * 2LL) % M;
}

const long long v = 499122177;
ip[0] = 1;
for (int i = 1; i < MX; i++) {
    ip[i] = (ip[i - 1] * v) % M;
}

while (t--) {
    int n;
    cin >> n;
    vector<int> a(n);

    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }

    long long r = 0;
    long long s = 0;
    int o = 0;
    int w = 0;

    for (int i = 0; i < n; i++) {
        if (a[i] == 1) {
            s = (s + ip[w]) % M;
            o++;
        } 
        else if (a[i] == 2) {
            w++;
        }
        else if (a[i] == 3) {
            long long c = ((p[w] * s) % M - o) % M;
            if (c < 0) {
                c += M;
            }
            r = (r + c) % M;
        }
    }

    cout << r << "\n";
}

return 0;

}

I think this is a bug or smt I want to say to [user:MikeMirzuhanov]plz reconsider the system desicion thsm