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 MAX = 2e5 + 9;
int n;
double a[MAX], sum[MAX];
double cal(double X) {
  double hsgs = 0, Mn = 0, Mx = 0;
  for (int i = 1; i <= n; i++) {
    sum[i] = sum[i - 1] + a[i] - X;
    hsgs = max(max(fabs(sum[i] - Mn), fabs(sum[i] - Mx)), hsgs);
    Mn = min(Mn, sum[i]), Mx = max(Mx, sum[i]);
  }
  return hsgs;
}
int main() {
  ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0);
  cin >> n;
  for (int i = 1; i <= n; i++) cin >> a[i];
  double l = -1e9 - 9, r = 1e9 + 9;
  for (int i = 1; i <= 250; i++)
    if (cal((2 * l + r) / 3) < cal((l + 2 * r) / 3))
      r = (l + 2 * r) / 3;
    else
      l = (2 * l + r) / 3;
  cout << fixed << setprecision(10) << cal(l);
}
