Submission #1372994

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Source Code Expand

#include <bits/stdc++.h>
 
#define pii pair<int, int>
#define f first
#define s second
#define pb push_back
#define mp make_pair
#define ll long long 
#define ull unsigned long long 
#define ld long double
#define sz(v) int(v.size())
#define all(v) v.begin(), v.end()
 
#define y1 what
 
using namespace std;
 
const int N = (int) 1e6 + 10;
const int M = (int) 101;
const ll big =  (1LL << 51);
const ll LINF = (ll) 1e18;
const int INF = (int) 1e9 + 7;
const int INF1 = (int) 1e9 + 3;
const double EPS = (double) 1e-6;
const double PI =  3.14159265359;
 
int n;
int a[N], b[N];
 
int main() {
    #define fn "balls"
    #ifdef witch
        freopen("input.txt", "r", stdin);
        freopen("output.txt", "w", stdout);
    #else
//        freopen(fn".in", "r", stdin);
//        freopen(fn".out", "w", stdout);
    #endif
    srand(time(0));
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    for (int i = 0; i < n; i++) {
        b[i] = a[(i + 1) % n] - a[i];
    }
    ll sum1 = 0, sum2 = (n * 1ll * (n + 1)) / 2;
    for (int i = 0; i < n; i++) {
        sum1 += a[i];
    }
    if (sum1 % sum2) {
        cout << "NO";
        return 0;
    }
    ll cnt = sum1 / sum2;
    sum1 = 0;
    for (int i = 0; i < n; i++) {
        if ((cnt - b[i]) % n) {
            sum1 = -1;
            break;
        }
        sum1 += (cnt - b[i]) / n;
    }
    if (sum1 == cnt) {
        cout << "YES";
    } else {
        cout << "NO";
    }
    return 0;
}

Submission Info

Judge Result