学步园

#include<cstdio>
#include<iostream>
#include<algorithm>
#define ll long long
using namespace std;
int n,a[1000001],c[1000001],ave;ll sum;
int main()
{
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
    {
        scanf("%d",&a[i]);
        sum+=a[i];
    }
    ave=sum/n;
    for(int i=2;i<=n;i++)
       c[i]=c[i-1]+a[i]-ave;
    sort(c+1,c+n+1);
    ll ans=0;
    int mid=c[(n>>1)+1];
    for(int i=1;i<=n;i++)
       ans+=abs(c[i]-mid);
    printf("%lld",ans); 
    return 0;
}