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 main() {
  int n;
  cin >> n;
  vector<int> a(n), b(n);
  for (int i = 0; i < n; i++) cin >> a[i];
  double l = *min_element(a.begin(), a.end());
  double r = *max_element(a.begin(), a.end());
  double mx = 0, mn = 0;
  while (r - l > 1e-12) {
    double mid = (l + r) / 2, sum1 = 0, sum2 = 0;
    mx = mn = 0;
    for (int i = 0; i < n; i++) {
      sum1 += a[i] - mid;
      if (sum1 < 0) sum1 = 0;
      if (sum1 > mx) mx = sum1;
      sum2 += a[i] - mid;
      if (sum2 > 0) sum2 = 0;
      if (sum2 < mn) mn = sum2;
    }
    if (mx + mn > 0)
      l = mid;
    else
      r = mid;
  }
  printf("%.12f\n", max(mx, abs(mn)));
  return 0;
}
