/*
Bismillahir Rahmanir Rahim
Farsid
BUET
*/

#include <bits/stdc++.h>
using namespace std;

#define SET(a, x) memset((a), (x), sizeof(a))
#define ll long long
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define SZ(x) ((int)(x).size())
#define i64 ll
#define IN(A, B, C)  ((B) <= (A) && (A) <= (C))
#define MAX
#define xx first
#define yy second

typedef vector<int> VI;
typedef vector<string> VS;
typedef vector<double> VD;
typedef vector<ll> VL;
typedef pair<int,int> PII;
typedef pair<ll,ll> PLL;
const int inf=0x20202020;
const ll linf=(((i64)1)<<60)-1;
const ll mod=1000000007;
const double eps=1e-9;
const double pi=3.1415926535897932384626;

const int DX[]={1,0,-1,0},DY[]={0,1,0,-1};
ll powmod(ll a,ll b,ll mod) {ll res=1;a%=mod;for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;}
ll gcd(ll a,ll b) { return b?gcd(b,a%b):a;}
ll inv_mod(ll a,ll mod){return powmod(a,mod-2,mod);}

void print(double n)
{
    printf("%.9lf\n",n);
    //cout<<n<<endl;

}

double A[200009];
int n;

double f(double x)
{
    double ans=0,pos=0,neg=0;
    for(int i=0;i<n;i++){
        double a=A[i]-x;
        ans=max(ans,abs(a));
        pos+=a;
        if(pos<0)pos=0;
        neg+=a;
        if(neg>0)neg=0;
        ans=max(ans,pos);
        ans=max(ans,abs(neg));
    }
    return ans;
}

double t_search(double lo, double hi)
{
    double md1,md2,ans;
    for(int i=0;i<300;i++){
        md1=lo+(hi-lo)/3.0;
        md2=lo+(2*(hi-lo))/3.0;
        double a1=f(md1),a2=f(md2);
        if(a2<a1){
            lo=md1;
            ans=a2;
        }
        else{
            hi=md2;
            ans=a1;
        }
    }
    return ans;
}

int main()
{
	//freopen("far.in","r",stdin);
	//freopen("gadha.out","w",stdout);
    int i,j,k ,T,cas=0;
    //scanf("%d",&T);
    cin>>n;
    double mn=inf,mx=-inf;
    for(i=0;i<n;i++){
            cin>>A[i];
            mn=min(mn,A[i]);
            mx=max(mx,A[i]);
    }
    double ans=t_search(mn-10,mx+10);
    print(ans);
    return 0;
}
/*Test Cases


*/