Submission #2858334

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Source Code Expand

#include<bits/stdc++.h>

using namespace std;
#define int long long

const int N = 5e5 + 10;
const int MOD = 1e9 + 7;

int n, sum;
int a[N];

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cin >> n;
    for(int i = 0; i < n; ++i) {
        cin >> a[i];
        sum += a[i];
    }
    if(sum % (n*(n + 1) / 2) != 0)  {
        cout << "NO";
        return 0;
    }

    int res = -1;
    for(int i = 0 ; i < n ; ++i)    {
        int cur = a[(i + 1) % n] - a[i];
        cur %= n;
        if(cur < 0) cur += n;
        if(res < 0) res = cur;
        if(res != cur)  {
            cout << "NO";
            return 0;
        }
    }
    cout << "YES";
}

Submission Info

Judge Result