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

#include <bits/stdc++.h>
using namespace std;
const double eps = 1e-9;
double a[222222];
int n;
double check(double x) {
  double sum = 0;
  double ans = 0;
  for (int i = 0; i < n; i++) {
    if (sum + a[i] - x < a[i] - x) {
      sum = a[i] - x;
    } else
      sum += a[i] - x;
    ans = max(ans, sum);
  }
  sum = 0;
  for (int i = 0; i < n; i++) {
    if (sum + (-(a[i] - x)) < (-(a[i] - x))) {
      sum = (-(a[i] - x));
    } else
      sum += (-(a[i] - x));
    ans = max(ans, sum);
  }
  return ans;
}
int main(void) {
  scanf("%d", &n);
  for (int i = 0; i < n; i++) {
    scanf("%lf", &a[i]);
  }
  double l = -1e9;
  double r = 1e9;
  double ans;
  double mid;
  double mmid;
  for (int i = 0; i < 700; i++) {
    mid = l + (r - l) / 3.0;
    mmid = r - (r - l) / 3.0;
    if (check(mid) <= check(mmid))
      r = mmid;
    else
      l = mid;
  }
  printf("%f\n", check(l));
  return 0;
}
