Submission #1093586

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Source Code Expand

#include<bits/stdc++.h>
 
using namespace std;
 
#define pb push_back
#define mp make_pair
#define F first
#define S second
 
#define fo(i, n) for(int i = 1; i <= n; ++i)
#define rep(i, a, b) for(int (i) = (a); (i) < (b); ++(i))
 
typedef long long ll;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
 
const int N = 200200;
const int mod = 1e9 + 7;
const ll INF = 1e18;
ll a[N],b[N],pref[N];
 
int main()
{
	ios::sync_with_stdio(0); cin.tie(0);
	int n;
	cin>>n;
	for(int i=1;i<=n;++i)
	{
		cin>>a[i];
		b[i]=i-a[i];
		pref[i]=pref[i-1]+a[i];
	}
	ll k=(n*1ll*(n+1)/2);
	if(pref[n]%k!=0)
		return cout<<"NO",0;
	ll x=pref[n]/k;
	a[n+1]=a[1];
	a[n+2]=a[2];
	ll cnt=0;
	ll cc=0;
	for(int i=2;i<=n+2;++i)
	{
		ll y=a[i]-a[i-1];
		b[i]=y;
		if(i>2&&b[i]!=b[i-1])
		{                 
			if(abs(b[i]-b[i-1])%n!=0||abs(b[i]-b[i-1])%5!=0)
				return cout<<"NO",0;
		}
	}
	if(cc<=x)
		cout<<"YES";
	else cout<<"NO";
	return 0;	
}

Submission Info

Judge Result