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.InputStream;
import java.io.InputStreamReader;
import java.io.BufferedReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.IOException;
import java.util.StringTokenizer;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
	public static void main(String[] args) {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		InputReader in = new InputReader(inputStream);
		PrintWriter out = new PrintWriter(outputStream);
		TaskC solver = new TaskC();
		solver.solve(1, in, out);
		out.close();
	}
}

class TaskC {

    public static double doit(int[] a, double x) {
        double max = 0;
        double curP = 0;
        double curN = 0;
        for (int i = 0; i < a.length; i++) {
            curP += a[i] - x;
            curN += a[i] - x;
            max = Math.max(max, curP);
            max = Math.max(max, -curN);
            if (curP < 0) {
                curP = 0;
            }
            if (curN > 0) {
                curN = 0;
            }
        }
        return max;
    }

    public void solve(int testNumber, InputReader in, PrintWriter out) {
        int n = in.nextInt();
        double t1 = Integer.MAX_VALUE, t2 = Integer.MIN_VALUE;
        int[] a = new int[n];
        for (int i = 0; i < n; i++) {
            a[i] = in.nextInt();
            t1 = Math.min(a[i] * 1.0, t1);
            t2 = Math.max(a[i] * 1.0, t2);
        }
        for (int i = 0; i < 100; i++) {
            double third = (t2 - t1) / 3;
            double m1 = t1 + third;
            double m2 = t1 + 2 * third;
            if (doit(a, m1) > doit(a, m2)) {
                t1 = m1;
            } else {
                t2 = m2;
            }
        }
        out.println(String.format("%.12f", Math.min(doit(a, t1), doit(a, t2))));
    }
}

class InputReader {
    public BufferedReader reader;
    public StringTokenizer tokenizer;

    public InputReader(InputStream stream) {
        reader = new BufferedReader(new InputStreamReader(stream), 32768);
        tokenizer = null;
    }

    public String next() {
        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken();
    }

    public int nextInt() {
        return Integer.parseInt(next());
    }
}

