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 p[200002], p2[200002], n;
double f(double c) {
  double a = 0, b = 0;
  for (int i = 0; i < n; i++) p2[i] = p[i] - c;
  double s = 0;
  for (int i = 0; i < n; i++) {
    if (s < 0) s = 0;
    s += p2[i];
    a = max(a, s);
  }
  s = 0;
  for (int i = 0; i < n; i++) {
    if (s > 0) s = 0;
    s += p2[i];
    b = min(b, s);
  }
  return max(fabs(b), fabs(a));
}
int main() {
  cin >> n;
  for (int i = 0; i < n; i++) cin >> p[i];
  double l = -1e18, r = 1e18;
  while (abs(l - r) >= 1e-10) {
    double lo = l + (r - l) / 3.;
    double hi = r - (r - l) / 3.;
    if (f(lo) <= f(hi))
      r = hi;
    else
      l = lo;
  }
  cout << fixed << setprecision(9) << f(l) << endl;
}
