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>
struct compMinPQ {
  bool operator()(const int &a, const int &b) { return a > b; }
};
using namespace std;
double a[200005];
int N;
double f(double x) {
  int i, j, k;
  for (i = 1; i <= N; i++) a[i] = a[i] - x;
  double max_so_far = a[1], max_ending = a[1];
  for (i = 2; i <= N; i++) {
    max_ending = max(a[i], max_ending + a[i]);
    max_so_far = max(max_so_far, max_ending);
  }
  double min_so_far = a[1], min_ending = a[1];
  for (i = 2; i <= N; i++) {
    min_ending = min(a[i], min_ending + a[i]);
    min_so_far = min(min_ending, min_so_far);
  }
  for (i = 1; i <= N; i++) a[i] = a[i] + x;
  return max(abs(max_so_far), abs(min_so_far));
}
int main() {
  int i, j, k;
  cin >> N;
  for (i = 1; i <= N; i++) cin >> a[i];
  double low = -10005;
  double high = 10005;
  double esp = 1e-13;
  double ans;
  for (i = 0; i < 200; i++) {
    double mid1 = low + (high - low) / 3.0;
    double mid2 = high - (high - low) / 3.0;
    if (f(mid1) - f(mid2) > esp) {
      ans = mid2;
      low = mid1 + esp;
    } else {
      ans = mid1;
      high = mid2 - esp;
    }
  }
  ans = f(ans);
  printf("%.12f\n", ans);
  return 0;
}
