10
-405 -230 252 -393 -390 -259 97 163 81 -129
 3
10000 -10000 10000
 1
-10000
 20
-16 -23 29 44 -40 -50 -41 34 -38 30 -12 28 -44 -49 15 50 -28 38 -2 0

702.333333333333712
 10000.000000000016371
 0.000000000000000
 113.875000000000043

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Random;
import java.util.StringTokenizer;
import java.util.stream.IntStream;

public class Solution{
	
	static final int N = (int)2e5+10;
	static int n;
	static int[] a;
	static double[] b;
	static double maxp, maxn;
	
	
	
    public static void main(String[] args) throws IOException {
    	
		
    	FastScanner fs = new FastScanner();
    	PrintWriter out = new PrintWriter(System.out);
    		
    	int tt = 1;
    	while(tt-->0) {
    		
    		n = fs.nextInt();
    		a = fs.readArray(n);
    		b = new double[n];
    		
    		int min = IntStream.of(a).min().getAsInt();
    		int max = IntStream.of(a).max().getAsInt();
    		
    		double l = min, r = max;
    		
    		for(int i=0;i<100;i++) {
    			double mid = (l+r)/2;
    			calc(mid);
    			if(maxp>maxn) l = mid;
    			else r = mid;
    		}
    		
    		double x = (l+r)/2;
    		calc(x);
    		out.println(Math.max(maxp, maxn));
    		
    		
    		
    		
    		
    		
    		
    	}
    	
    	out.close();
    		
    }
   
    
    static void calc(double x) {
    	for(int i=0;i<n;i++) {
    		b[i] = a[i] - x;
    	}
    	maxp = mcs();
    	for(int i=0;i<n;i++) b[i] *= -1;
    	maxn = mcs();
    }
    
    static double mcs() {
    	double max = 0, cur = 0;
    	for(int i=0;i<n;i++) {
    		cur = Math.max(cur+b[i], 0);
    		max = Math.max(max, cur);
    	}
    	return max;
    }
   
    
    
    
    static final Random random=new Random();
    
    static <T> void shuffle(T[] arr) {
    	int n = arr.length;
    	for(int i=0;i<n;i++	) {
    		int k = random.nextInt(n);
    		T temp = arr[k]; arr[k] = arr[i]; arr[i] = temp;
    	}
    }
    
    	
    static void ruffleSort(int[] a) {
    	int n=a.length;//shuffle, then sort 
    	for (int i=0; i<n; i++) {
    		int oi=random.nextInt(n); int temp=a[oi];
    		a[oi]=a[i]; a[i]=temp;
    	}
    	Arrays.sort(a);
    }
    
    static void ruffleSort(long[] a) {
    	int n=a.length;//shuffle, then sort 
    	for (int i=0; i<n; i++) {
    		int oi=random.nextInt(n); long temp=a[oi];
    		a[oi]=a[i]; a[i]=temp;
    	}
    	Arrays.sort(a);
    }
   
  
    
    static void reverse(int[] arr, int l, int r) {
    	for(int i=l;i<l+(r-l)/2;i++){
    		int temp = arr[i]; arr[i] = arr[r-i+l-1]; arr[r-i+l-1] = temp;
    	}
    }
    
    static void reverse(long[] arr, int l, int r) {
    	for(int i=l;i<l+(r-l)/2;i++){
    		long temp = arr[i]; arr[i] = arr[r-i+l-1]; arr[r-i+l-1] = temp;
    	}
    }
    
    
    static <T> void reverse(T[] arr, int l, int r) {
    	for(int i=l;i<l+(r-l)/2;i++) {
    		T temp = arr[i]; arr[i] = arr[r-i+l-1]; arr[r-i+l-1] = temp;
    	}
    }
    	
    	
    static class FastScanner{
    	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    	StringTokenizer st = new StringTokenizer("");
     
    	public String next(){
    		while(!st.hasMoreElements()){
    			try{
    				st = new StringTokenizer(br.readLine());
    			} catch(IOException e){
    				e.printStackTrace();
    			}
    		}
    		return st.nextToken();
    	}
    		
    	public String nextLine() throws IOException {
    		return br.readLine();
    	}
    		
    	public int nextInt(){
    		return Integer.parseInt(next());
    	}
     
    	public int[] readArray(int n){
    		int[] a = new int[n];
    		for(int i=0;i<n;i++)
    			a[i] = nextInt();
    		return a;
    	}
    		
    	public long nextLong() {
    		return Long.parseLong(next());
    	}
    		
    	public char nextChar() {
    		return next().toCharArray()[0];
    	}
    }
   	
}
