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;
int n;
int A[200000];
double T[200001];
double weakness(double x) {
  T[0] = 0;
  for (int i = 0; i < n; i++) {
    T[i + 1] = T[i] + A[i] - x;
  }
  double mn = T[n], mx = T[n], mxw = 0;
  for (int i = n - 1; i >= 0; i--) {
    mxw = max(mxw, max(abs(mx - T[i]), abs(mn - T[i])));
    if (T[i] > mx) mx = T[i];
    if (T[i] < mn) mn = T[i];
  }
  return mxw;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cin >> n;
  for (int i = 0; i < n; i++) cin >> A[i];
  int amn = A[0], amx = A[0];
  for (int i = 0; i < n; i++) {
    if (amn > A[i]) amn = A[i];
    if (amx < A[i]) amx = A[i];
  }
  double l = amn, r = amx;
  for (int i = 0; i < 300; i++) {
    double step = (r - l) / 3;
    double m1 = weakness(l + step), m2 = weakness(r - step);
    if (m1 < m2)
      r -= step;
    else
      l += step;
  }
  cout << fixed << setprecision(10) << weakness(l) << "\n";
  return 0;
}
