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;
double n, a[200005], sum[200005];
const double EPS = 0.000000000005;
double f(double x) {
  double ans = -999999999, t_sum = 0, max_sum = -999999999, min_sum = 999999999,
         temp;
  for (int i = 0; i < n; i++) {
    t_sum += a[i] - x;
    sum[i] = t_sum;
  }
  for (int i = 0; i < n; i++) {
    ans = max(ans, abs(sum[i]));
    if (i != 0) {
      if (sum[i] < 0) {
        temp = sum[i] - max_sum;
        ans = max(ans, abs(temp));
      } else {
        temp = sum[i] - min_sum;
        ans = max(ans, abs(temp));
      }
    }
    if (sum[i] > max_sum) {
      max_sum = sum[i];
    }
    if (sum[i] < min_sum) {
      min_sum = sum[i];
    }
  }
  return ans;
}
double solve() {
  double l = -10000, r = 10000, m1, m2;
  while (r - l > EPS) {
    m1 = l + (r - l) / 3;
    m2 = r - (r - l) / 3;
    if (f(m1) < f(m2)) {
      r = m2;
    } else {
      l = m1;
    }
  }
  return r;
}
int main() {
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  cout << fixed << setprecision(7) << f(solve());
  return 0;
}
