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 INF = 2147483647, MOD = 1000 * 1000 * 1000 + 7;
const double eps = 1e-8;
void Error(string err) {
  cout << err;
  cerr << "_" << err << "_";
  exit(0);
}
int gcd(int a, int b) { return (b == 0) ? a : gcd(b, a % b); }
const int sz = 222 * 1000;
int arr[sz], arr2[sz];
double sum[sz];
int n;
double f(double x) {
  double ret = 0;
  double sm = 0;
  for (int i = 0; i < (n); i++) {
    if (sm + arr[i] - x > arr[i] - x)
      sm += arr[i] - x;
    else
      sm = arr[i] - x;
    ret = max(ret, abs(sm));
  }
  sm = 0;
  for (int i = 0; i < (n); i++) {
    if (sm + arr[i] - x < arr[i] - x)
      sm += arr[i] - x;
    else
      sm = arr[i] - x;
    ret = max(ret, abs(sm));
  }
  return ret;
}
int main() {
  cin >> n;
  for (int i = 0; i < (n); i++) cin >> arr[i];
  sum[0] = arr[0];
  for (int i = 1; i <= (n - 1); i++) sum[i] = sum[i - 1] + arr[i];
  for (int i = 0; i < (n); i++) arr2[i] = arr[i];
  sort(arr2, arr2 + n);
  double a = arr2[n / 2];
  double wa = f(a);
  double inc = (arr2[n - 1] - arr2[0]);
  while (true) {
    wa = f(a);
    double nwai = f(a + inc), nwad = f(a - inc);
    if (wa > nwai && wa < nwad)
      a += inc;
    else if (wa > nwad && wa < nwai)
      a -= inc;
    else
      inc /= 2;
    double x = wa - nwai;
    double y = wa - nwad;
    double z = nwai - nwad;
    x = abs(x) + abs(y) + abs(z);
    if (x < 1e-9) break;
  }
  cout.setf(ios::fixed);
  cout.precision(8);
  cout << wa << endl;
  return 0;
}
