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 int N = (int)2e5 + 5;
int a[N];
int n;
double f(double x) {
  double mn = a[0] - x;
  double mx = a[0] - x;
  double cur_mn = mn, cur_mx = mx;
  for (int i = 1; i < n; i++) {
    cur_mx = max(a[i] - x, cur_mx + a[i] - x);
    cur_mn = min(a[i] - x, cur_mn + a[i] - x);
    mx = max(mx, cur_mx);
    mn = min(mn, cur_mn);
  }
  return max(fabs(mn), mx);
}
int main() {
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  double l = -1e9, r = 1e9;
  for (int i = 0; i < 500; i++) {
    double m1 = l + (r - l) / 3.0;
    double m2 = r - (r - l) / 3.0;
    if (f(m1) > f(m2)) {
      l = m1;
    } else
      r = m2;
  }
  cout << fixed;
  cout << setprecision(15) << f(l) << endl;
}
