Submission #34503344

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Source Code Expand

#include <bits/stdc++.h>

using i64 = long long;

const int N = 1e5 + 5;

int n;
i64 a[N];

int main() {
    std::cin >> n;
    i64 sum = 0; 
    for (int i = 0; i < n; i++) {
        std::cin >> a[i]; 
        sum += a[i]; 
    }
    if (sum % (1ll * (n + 1) * n / 2) != 0) {
        std::cout << "NO\n";
        return 0; 
    }
    i64 k = sum / (1ll * (n + 1) * n / 2);
    i64 ans = 0; 
    bool flag = 1; 
    for (int i = 0; i < n; i++) {
        i64 dif = a[(i + 1) % n] - a[i]; 
        if ((k - dif) % n != 0 || k < dif) {
            flag = 0; 
            break; 
        }
        ans += (k - dif) / n; 
    }
    if (ans != k || !flag) {
        std::cout << "NO\n"; 
    } else {
        std::cout << "YES\n"; 
    }
    return 0; 
}

Submission Info

Judge Result