问离谱大样例

#include<bits/stdc++.h>
using namespace std;
#define int long long
const int N=1e6+5;
inline void read(int &x){
	char ch=getchar();
	int q=1;x=0;
	while(ch<'0'||ch>'9'){
		if(ch=='-'){
			q=-1;
		}
		ch=getchar();
	}
	while(ch>='0'&&ch<='9'){
		x=x*10+ch-'0';
		ch=getchar();
	}
	x=x*q;
	return;
}
int use[N],val[N];
int n,mx,res,mi;
void dfs(int d,int now,int sum1,int sum2,int last,bool op){
	if(op==0){
		for(int i=last;i>=0;--i){
			if(use[i]!=0){
				use[i]--;
				if(i==mi){
					dfs(d+1,now+i,sum1+(now+i)*(now+i)*n,sum2+now+i,i,1);
				}else{
					dfs(d+1,now+i,sum1+(now+i)*(now+i)*n,sum2+now+i,i,0); 
				}
				use[i]++;
			}
		}
	}else{
		for(int i=last;i<=mx;++i){
			for(int j=1;j<=use[i];++j){
				now=now+i;
				sum1=sum1+now*now*n;
				sum2=sum2+now;
			}
		}
		res=min(res,sum1-sum2*sum2);
		return;
	}
}
signed main(){
	//freopen("variance.in","r",stdin);
	//freopen("variance.out","w",stdout);
	read(n);
	mi=1e9;
	for(int i=1;i<=n;++i){
		read(val[i]);
		if(i==1){
			continue;
		}
		int d=val[i]-val[i-1];
		use[d]++;
		mx=max(mx,d);
		mi=min(mi,d);
	}
	res=1e9;
	dfs(1,0,0,0,mx,0);
	cout<<res<<"\n";
	return 0;
}