Submission #19550525

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Source Code Expand

#include <bits/stdc++.h>

using namespace std;
long long n, ans=1, mod=998244353, ert=1;
void oszt(long long a) {
    long long p=mod-2;
    while (p) {
        if (p%2) {
            ans*=a, ans%=mod;
        }
        a*=a, a%=mod;
        p/=2;
    }
}
int main()
{
    cin >> n;
    for (int i=1; i<=2*n; i++) {
        ert*=i, ert%=mod;
        if (i==2) {
            oszt(ert);
        }
        if (i==n) {
            oszt(ert), oszt(ert);
        }
    }
    cout << ans*ert%mod << "\n";
    return 0;
}

Submission Info

Judge Result