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 n, seq[200000];
double eval(double x) {
  double csum = 0, cmin = 0, cmax = 0, ans = 0;
  for (int i = 0; i < n; i++) {
    csum += (seq[i] - x);
    cmin = min(cmin, csum), cmax = max(cmax, csum);
    ans = max(ans, max(csum - cmin, cmax - csum));
  }
  return ans;
}
int main() {
  scanf("%d", &n);
  for (int i = 0; i < n; i++) scanf("%d", &seq[i]);
  double l = -10000, r = 10000, E = 0.00000000001;
  while (r - l > 0.00000000001) {
    double m1 = l + (r - l) / 3, m2 = r - (r - l) / 3;
    if (eval(m1) < eval(m2))
      r = m2;
    else
      l = m1;
  }
  cout << fixed << setprecision(10) << eval((l + r) / 2);
}
